diff --git a/python/HISTORY.md b/python/HISTORY.md
index 8001c9bba2c..69d85ad9f25 100644
--- a/python/HISTORY.md
+++ b/python/HISTORY.md
@@ -1,7 +1,27 @@
 # HISTORY 
 
+## May 1st
+
+**0.8.1**
+
+* Fix metric unit casting logic if one passes plain string (value or key)
+* Fix `MetricUnit` enum values for
+    - `BytesPerSecond`
+    - `KilobytesPerSecond`
+    - `MegabytesPerSecond`
+    - `GigabytesPerSecond`
+    - `TerabytesPerSecond`
+    - `BitsPerSecond`
+    - `KilobitsPerSecond`
+    - `MegabitsPerSecond`
+    - `GigabitsPerSecond`
+    - `TerabitsPerSecond`
+    - `CountPerSecond`
+
 ## April 24th
 
+**0.8.0**
+
 * Introduces `Logger` for stuctured logging as a replacement for `logger_setup`
 * Introduces `Logger.inject_lambda_context` decorator as a replacement for `logger_inject_lambda_context`
 * Raise `DeprecationWarning` exception for both `logger_setup`, `logger_inject_lambda_context`
diff --git a/python/aws_lambda_powertools/helper/models.py b/python/aws_lambda_powertools/helper/models.py
index 424e5bf3aef..16a5df3669e 100644
--- a/python/aws_lambda_powertools/helper/models.py
+++ b/python/aws_lambda_powertools/helper/models.py
@@ -89,17 +89,17 @@ class MetricUnit(Enum):
     Terabits = "Terabits"
     Percent = "Percent"
     Count = "Count"
-    BytesPerSecond = "Second"
-    KilobytesPerSecond = "Second"
-    MegabytesPerSecond = "Second"
-    GigabytesPerSecond = "Second"
-    TerabytesPerSecond = "Second"
-    BitsPerSecond = "Second"
-    KilobitsPerSecond = "Second"
-    MegabitsPerSecond = "Second"
-    GigabitsPerSecond = "Second"
-    TerabitsPerSecond = "Second"
-    CountPerSecond = "Second"
+    BytesPerSecond = "Bytes/Second"
+    KilobytesPerSecond = "Kilobytes/Second"
+    MegabytesPerSecond = "Megabytes/Second"
+    GigabytesPerSecond = "Gigabytes/Second"
+    TerabytesPerSecond = "Terabytes/Second"
+    BitsPerSecond = "Bits/Second"
+    KilobitsPerSecond = "Kilobits/Second"
+    MegabitsPerSecond = "Megabits/Second"
+    GigabitsPerSecond = "Gigabits/Second"
+    TerabitsPerSecond = "Terabits/Second"
+    CountPerSecond = "Count/Second"
 
 
 def build_metric_unit_from_str(unit: Union[str, MetricUnit]) -> MetricUnit:
diff --git a/python/aws_lambda_powertools/metrics/base.py b/python/aws_lambda_powertools/metrics/base.py
index 8d561abf71d..38e513f19a8 100644
--- a/python/aws_lambda_powertools/metrics/base.py
+++ b/python/aws_lambda_powertools/metrics/base.py
@@ -53,6 +53,8 @@ def __init__(self, metric_set: Dict[str, str] = None, dimension_set: Dict = None
         self.metric_set = metric_set or {}
         self.dimension_set = dimension_set or {}
         self.namespace = os.getenv("POWERTOOLS_METRICS_NAMESPACE") or namespace
+        self._metric_units = [unit.value for unit in MetricUnit]
+        self._metric_unit_options = list(MetricUnit.__members__)
 
     def add_namespace(self, name: str):
         """Adds given metric namespace
@@ -105,14 +107,8 @@ def add_metric(self, name: str, unit: MetricUnit, value: Union[float, int]):
         if not isinstance(value, numbers.Number):
             raise MetricValueError(f"{value} is not a valid number")
 
-        if not isinstance(unit, MetricUnit):
-            try:
-                unit = MetricUnit[unit]
-            except KeyError:
-                unit_options = list(MetricUnit.__members__)
-                raise MetricUnitError(f"Invalid metric unit '{unit}', expected either option: {unit_options}")
-
-        metric = {"Unit": unit.value, "Value": float(value)}
+        unit = self.__extract_metric_unit_value(unit=unit)
+        metric = {"Unit": unit, "Value": float(value)}
         logger.debug(f"Adding metric: {name} with {metric}")
         self.metric_set[name] = metric
 
@@ -205,3 +201,36 @@ def add_dimension(self, name: str, value: str):
         """
         logger.debug(f"Adding dimension: {name}:{value}")
         self.dimension_set[name] = value
+
+    def __extract_metric_unit_value(self, unit: Union[str, MetricUnit]) -> str:
+        """Return metric value from metric unit whether that's str or MetricUnit enum
+
+        Parameters
+        ----------
+        unit : Union[str, MetricUnit]
+            Metric unit
+
+        Returns
+        -------
+        str
+            Metric unit value (e.g. "Seconds", "Count/Second")
+
+        Raises
+        ------
+        MetricUnitError
+            When metric unit is not supported by CloudWatch
+        """
+
+        if isinstance(unit, str):
+            if unit in self._metric_unit_options:
+                unit = MetricUnit[unit].value
+
+            if unit not in self._metric_units:  # str correta
+                raise MetricUnitError(
+                    f"Invalid metric unit '{unit}', expected either option: {self._metric_unit_options}"
+                )
+
+        if isinstance(unit, MetricUnit):
+            unit = unit.value
+
+        return unit
diff --git a/python/pyproject.toml b/python/pyproject.toml
index 8b21c9dce86..99a3564ca22 100644
--- a/python/pyproject.toml
+++ b/python/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "aws_lambda_powertools"
-version = "0.8.0"
+version = "0.8.1"
 description = "Python utilities for AWS Lambda functions including but not limited to tracing, logging and custom metric"
 authors = ["Amazon Web Services"]
 classifiers=[
diff --git a/python/tests/functional/test_metrics.py b/python/tests/functional/test_metrics.py
index 703c8788ac1..7c6990668bc 100644
--- a/python/tests/functional/test_metrics.py
+++ b/python/tests/functional/test_metrics.py
@@ -303,3 +303,28 @@ def lambda_handler(evt, context):
 
     with pytest.raises(SchemaValidationError):
         lambda_handler({}, {})
+
+
+def test_all_metric_units_string(metric, dimension, namespace):
+
+    # metric unit as MetricUnit key e.g. "Seconds", "BytesPerSecond"
+    for unit in MetricUnit:
+        metric["unit"] = unit.name
+        with single_metric(**metric) as my_metric:
+            my_metric.add_dimension(**dimension)
+            my_metric.add_namespace(**namespace)
+
+    with pytest.raises(MetricUnitError):
+        metric["unit"] = "seconds"
+        with single_metric(**metric) as my_metric:
+            my_metric.add_dimension(**dimension)
+            my_metric.add_namespace(**namespace)
+
+    all_metric_units = [unit.value for unit in MetricUnit]
+
+    # metric unit as MetricUnit value e.g. "Seconds", "Bytes/Second"
+    for unit in all_metric_units:
+        metric["unit"] = unit
+        with single_metric(**metric) as my_metric:
+            my_metric.add_dimension(**dimension)
+            my_metric.add_namespace(**namespace)