diff --git a/cpp/src/arrow/compare.cc b/cpp/src/arrow/compare.cc
index b515fdd165d..26f56d9b588 100644
--- a/cpp/src/arrow/compare.cc
+++ b/cpp/src/arrow/compare.cc
@@ -71,8 +71,6 @@ using util::Float16;
 
 namespace {
 
-// TODO also handle HALF_FLOAT NaNs
-
 template <bool Approximate, bool NansEqual, bool SignedZerosEqual>
 struct FloatingEqualityFlags {
   static constexpr bool approximate = Approximate;