diff --git a/src/attr/validators.py b/src/attr/validators.py
index 0b1a29443..b1610738f 100644
--- a/src/attr/validators.py
+++ b/src/attr/validators.py
@@ -343,8 +343,13 @@ def __call__(self, inst, attr, value):
         if self.iterable_validator is not None:
             self.iterable_validator(inst, attr, value)
 
-        for member in value:
-            self.member_validator(inst, attr, member)
+        for idx, member in enumerate(value):
+            try:
+                self.member_validator(inst, attr, member)
+            except (ValueError, TypeError) as e:
+                # Re-raise with context about which member failed
+                msg = str(e).replace(f"'{attr.name}'", f"'{attr.name}[{idx}]'")
+                raise type(e)(msg) from None
 
     def __repr__(self):
         iterable_identifier = (
@@ -399,9 +404,21 @@ def __call__(self, inst, attr, value):
 
         for key in value:
             if self.key_validator is not None:
-                self.key_validator(inst, attr, key)
+                try:
+                    self.key_validator(inst, attr, key)
+                except (ValueError, TypeError) as e:
+                    msg = str(e).replace(
+                        f"'{attr.name}'", f"'{attr.name}[key:{key!r}]'"
+                    )
+                    raise type(e)(msg) from None
             if self.value_validator is not None:
-                self.value_validator(inst, attr, value[key])
+                try:
+                    self.value_validator(inst, attr, value[key])
+                except (ValueError, TypeError) as e:
+                    msg = str(e).replace(
+                        f"'{attr.name}'", f"'{attr.name}[{key!r}]'"
+                    )
+                    raise type(e)(msg) from None
 
     def __repr__(self):
         return f"<deep_mapping validator for objects mapping {self.key_validator!r} to {self.value_validator!r}>"