A new case of acute monocytic leukemia observed in a 73-year-old male (ANLLM5) with an unusual t(8;22)(p11;q13) is reported. The blasts did not demonstrate erythrophagocytosis, but the presence of both naphthol-ASD-chloro-acetate esterase and butyrate esterase activities was similar to that seen in cases with t(8;16)(p11;p13). Involvement of the 8p11 region in ANLLM4 and M5 is discussed, being the third most frequent rearrangement in acute leukemia with monocytic components seen at our Center.