diff --git a/cpp/src/arrow/util/tdigest.cc b/cpp/src/arrow/util/tdigest.cc
index 36a83fb336d..7d9e316cd30 100644
--- a/cpp/src/arrow/util/tdigest.cc
+++ b/cpp/src/arrow/util/tdigest.cc
@@ -168,10 +168,6 @@ class TDigest::TDigestImpl {
     if (total_weight != total_weight_) {
       return Status::Invalid("tdigest total weight mismatch");
     }
-    // check if buffer expanded
-    if (tdigests_[0].capacity() > delta_ || tdigests_[1].capacity() > delta_) {
-      return Status::Invalid("oversized tdigest buffer");
-    }
     // check k-size
     return merger_.Validate(tdigests_[current_], total_weight_);
   }