The association of acute myeloid leukemia (AML) with plasmacytosis is a known, although rare event. There are very few case reports documenting an increase in the number of plasma cells at the time of AML diagnosis. Here, we present the case of a 65-year-old male diagnosed as acute myelomonocytic leukemia with exuberant plasmacytosis, which posed a difficulty in diagnosis. Paracrine interleukin-6 production by leukemic blast cells is thought to contribute to this associated reactive plasma cell proliferation.