diff --git a/lm_eval/base.py b/lm_eval/base.py
index 16707d771b..63eb38efc8 100644
--- a/lm_eval/base.py
+++ b/lm_eval/base.py
@@ -652,8 +652,6 @@ class PromptSourceTask(Task):
     added default behavior for. If you want to add default behavior for a new metric,
     update the functions below. If you want to use one of the following metrics,
     *and* add additional custom processing, override `process_results`, `higher_is_better`, and `aggregation`.
-
-    WARNING: ROUGE is WIP.
     """
 
     CONFIGURED_PS_METRICS = set(["Accuracy", "BLEU", "ROUGE"])
@@ -765,7 +763,6 @@ def process_results(self, doc, results):
             # NOTE: In the future, target will be a list of strings.
             pred = results[0].strip()
             out = {}
-
             for metric in self.prompt.metadata.metrics:
                 assert (
                     metric in self.CONFIGURED_PS_METRICS
@@ -773,8 +770,15 @@ def process_results(self, doc, results):
                 if metric == "BLEU":
                     out["bleu"] = (target, pred)
                 if metric == "ROUGE":
-                    print("WARNING: Skipping Rouge.")
-
+                    # TODO: This computes all rouge sub-metrics. Find a generic
+                    # way to handle user specified rouge sub-metrics to avoid extra
+                    # compute.
+                    rouge_scores = metrics.rouge(target, pred)
+                    # Flatten rouge score dict.
+                    rouge_scores = utils.flatten(rouge_scores)
+                    # Merge all the rouge-type scores into the `out` dict.
+                    out = {**out, **rouge_scores}
+                    print(out)
             return out
 
     def higher_is_better(self):
@@ -788,7 +792,22 @@ def higher_is_better(self):
             if metric == "BLEU":
                 out["bleu"] = True
             if metric == "ROUGE":
-                print("WARNING: Skipping Rouge.")
+                # TODO: Find a generic way to handle user specified rouge metrics.
+                out["rouge1_precision"] = True
+                out["rouge1_recall"] = True
+                out["rouge1_fmeasure"] = True
+
+                out["rouge2_precision"] = True
+                out["rouge2_recall"] = True
+                out["rouge2_fmeasure"] = True
+
+                out["rougeL_precision"] = True
+                out["rougeL_recall"] = True
+                out["rougeL_fmeasure"] = True
+
+                out["rougeLsum_precision"] = True
+                out["rougeLsum_recall"] = True
+                out["rougeLsum_fmeasure"] = True
         return out
 
     def aggregation(self):
@@ -802,7 +821,22 @@ def aggregation(self):
             if metric == "BLEU":
                 out["bleu"] = metrics.bleu
             if metric == "ROUGE":
-                print("WARNING: Skipping Rouge.")
+                # TODO: Find a generic way to handle user specified rouge metrics.
+                out["rouge1_precision"] = mean
+                out["rouge1_recall"] = mean
+                out["rouge1_fmeasure"] = mean
+
+                out["rouge2_precision"] = mean
+                out["rouge2_recall"] = mean
+                out["rouge2_fmeasure"] = mean
+
+                out["rougeL_precision"] = mean
+                out["rougeL_recall"] = mean
+                out["rougeL_fmeasure"] = mean
+
+                out["rougeLsum_precision"] = mean
+                out["rougeLsum_recall"] = mean
+                out["rougeLsum_fmeasure"] = mean
         return out
 
 
diff --git a/lm_eval/metrics.py b/lm_eval/metrics.py
index 38f60ab52b..ba91e0c2ee 100644
--- a/lm_eval/metrics.py
+++ b/lm_eval/metrics.py
@@ -202,6 +202,15 @@ def rouge(
     :param pred:
         A single prediction `str`s.
     """
+
+    # Add newlines between sentences to correctly compute `rougeLsum`.
+    if "rougeLsum" in rouge_types:
+        # TODO: Adapt this to handle languages that do not support sentence endings by `.`.
+        # See GEM-metrics implementation with lang specific `nltk` tokenizers to
+        # split sentences.
+        pred = pred.replace(".", ".\n")
+        refs = [ref.replace(".", ".\n") for ref in refs]
+
     scorer = rouge_scorer.RougeScorer(rouge_types=rouge_types, use_stemmer=True)
     # ROUGE multi-ref jackknifing
     if len(refs) > 1:
diff --git a/lm_eval/utils.py b/lm_eval/utils.py
index e331283866..b508db96f8 100644
--- a/lm_eval/utils.py
+++ b/lm_eval/utils.py
@@ -146,6 +146,19 @@ def get_original(self, newarr):
         
         return res
 
+
+def flatten(d, parent_key='', sep='_'):
+    # From: https://stackoverflow.com/a/6027615
+    items = []
+    for k, v in d.items():
+        new_key = parent_key + sep + k if parent_key else k
+        if isinstance(v, collections.MutableMapping):
+            items.extend(flatten(v, new_key, sep=sep).items())
+        else:
+            items.append((new_key, v))
+    return dict(items)
+
+
 def positional_deprecated(fn):
     """
     A decorator to nudge users into passing only keyword args (`kwargs`) to the