We present two patients with two cytogenetically unrelated clones. A patient was diagnosed of refractory anaemia and showed an abnormal clone with trisomy 8 and other clone with 5q-; the other patient, diagnosed as chronic lymphocytic leukaemia showed a clone with an inversion of chromosome 2, inv(2) (p23q12) and the other clone with a 47,XX,+5,t(16;17)(p13;q11),+2ac karyotype. The discussion is focused on the presence of unrelated clones in relation to the monoclonal origin of cancer.