Detailed chromosome studies, briefly reported previously, from short-term cultures of tumor cells from myxoid liposarcomas are reported. A common reciprocal translocation, t(12;16)(q13;p11), was found in three cases and a complex t(1;12;16)(p11;q13;p11) in the fourth one. This nonrandom primary change, not described before in solid tumors, could characterize the myxoid form of liposarcoma. The involvement of a closely located breakpoint on chromosome #12 in a reciprocal t(3;12)(q28;q14) described in a lipoma in the previous article of this series, suggests a common basis in the biological process of proliferation of tumors sharing a common histogenesis.