The neural adhesion molecule CD56 is normally expressed on natural killer cells and subsets of T cells and is commonly found in hematolymphoid neoplasms. Expression of CD56 is very rare in B-cell lymphoma and most reported CD56-positive cases were diffuse large B-cell lymphomas. Cases of CD56-positive mantle cell lymphoma (MCL) have not previously been described in the literature. We present a case of CD56-positive MCL. To the best of our knowledge, this is the first case report of MCL expressing CD56.