diff --git a/app/Main.hs b/app/Main.hs
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -209,7 +209,7 @@
                         , _birchSimMat              = simMat
                         }
 
-    (plot, _, _, _, tree', _) <- mainDiagram config
+    (plot, _, _, _, tree', gr) <- mainDiagram config
 
     -- Plot tree.
     D.renderCairo
@@ -219,6 +219,12 @@
 
     -- Write new tree if necessary.
     mapM_ (\x -> B.writeFile x . A.encode $ tree') . unHelpful . jsonOutput $ opts
+
+    -- Write the csv if necessary.
+    mapM_ (\x -> B.writeFile x . printNodeAssignments . getNodeAssignments $ gr)
+      . unHelpful
+      . csvOutput
+      $ opts
 
     when (unHelpful . interactive $ opts) $ interactiveDiagram tree labelMap (Nothing :: Maybe NamedMatrix) simMat
 
diff --git a/birch-beer.cabal b/birch-beer.cabal
--- a/birch-beer.cabal
+++ b/birch-beer.cabal
@@ -1,6 +1,6 @@
 cabal-version: >=1.10
 name: birch-beer
-version: 0.2.3.0
+version: 0.2.4.0
 license: GPL-3
 license-file: LICENSE
 copyright: 2019 Gregory W. Schwartz
diff --git a/src/BirchBeer/Options.hs b/src/BirchBeer/Options.hs
--- a/src/BirchBeer/Options.hs
+++ b/src/BirchBeer/Options.hs
@@ -20,6 +20,7 @@
     , inputMatrix :: Maybe String <?> "([Nothing] | FILE) The input adjacency matrix file for CollectionGraph (matrix market format if ends in .mtx, \"i,j,value\" without header otherwise and text labels will be sorted when converting indices)."
     , output :: Maybe String <?> "([dendrogram.svg] | FILE) The filename for the dendrogram. Supported formats are PNG, PS, PDF, and SVG."
     , jsonOutput :: Maybe String <?> "([Nothing] | FILE) The filename for the output json tree. The input tree can change based on pruning, so this option provides a way to output the new tree as a json."
+    , csvOutput :: Maybe String <?> "([Nothing] | FILE) The filename for the output csv containing node assignment for each item. The input tree can change based on pruning, so this option provides a way to view the new assignments as a csv."
     , delimiter :: Maybe Char <?> "([,] | CHAR) The delimiter for csv files."
     , labelsFile :: Maybe String <?> "([Nothing] | FILE) The input file containing the label for each item, with \"item,label\" header."
     , minSize :: Maybe Int <?> "([1] | INT) The minimum size of a cluster. Defaults to 1."
@@ -53,6 +54,7 @@
 modifiers = lispCaseModifiers { shortNameModifier = short }
   where
     short "customCut"            = Nothing
+    short "csvOutput"            = Nothing
     short "drawCollection"       = Just 'D'
     short "drawColors"           = Just 'R'
     short "drawDiscretize"       = Nothing
diff --git a/src/BirchBeer/Utility.hs b/src/BirchBeer/Utility.hs
--- a/src/BirchBeer/Utility.hs
+++ b/src/BirchBeer/Utility.hs
@@ -7,6 +7,7 @@
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE ViewPatterns #-}
 {-# LANGUAGE TupleSections #-}
+{-# LANGUAGE OverloadedStrings #-}
 
 module BirchBeer.Utility
     ( getMostFrequent
@@ -34,6 +35,8 @@
     , subsetLabelColorMap
     , getHighLowColors
     , closestColor
+    , getNodeAssignments
+    , printNodeAssignments
     ) where
 
 -- Remote
@@ -46,9 +49,12 @@
 import Data.Monoid ((<>))
 import Data.Tree (Tree (..), flatten)
 import Safe (atMay, headMay)
+import TextShow (showt)
 import qualified Control.Lens as L
 import qualified Data.Clustering.Hierarchical as HC
+import qualified Data.Csv as CSV
 import qualified Math.Clustering.Hierarchical.Spectral.Types as HSC
+import qualified Data.ByteString.Lazy.Char8 as B
 import qualified Data.Foldable as F
 import qualified Data.Graph.Inductive as G
 import qualified Data.Map.Strict as Map
@@ -373,3 +379,27 @@
 -- | Euclidean distance between two lists.
 euclideanDist :: [Double] -> [Double] -> Double
 euclideanDist xs = sqrt . sum . zipWith (\x y -> (x - y) ** 2) xs
+
+-- | Get a list of clusters for each item.
+getNodeAssignments :: (TreeItem a) => ClusterGraph a -> [(a, [Cluster])]
+getNodeAssignments =
+  concatMap (\ (!ns, (_, !xs))
+            -> zip (maybe [] F.toList xs) . repeat . fmap Cluster $ ns
+            )
+      . F.toList
+      . flip getGraphLeavesWithParents 0
+      . unClusterGraph
+
+-- | Print the node assignments.
+printNodeAssignments :: (TreeItem a) => [(a, [Cluster])] -> B.ByteString
+printNodeAssignments cr = header <> "\n" <> body
+  where
+    header = "item,cluster,path"
+    body = CSV.encode
+         . fmap (\ (!ci, !(c:cs))
+                -> ( unId . getId $ ci
+                   , showt $ unCluster c
+                   , T.intercalate "/" . fmap (showt . unCluster) $ c:cs
+                   )
+                 )
+         $ cr