The co-existence of both chronic myeloid leukemia (CML) and chronic lymphocytic leukemia (CLL) have been described in a few cases, either simultaneously or subsequently presenting. We report an unusual case of three he-matological malignancies in the same patient: CLL, CML, and acute myeloid leukemia (AML). None of the three malignancies shared the same origin, since the marrow sample was negative for BCR-ABL1 transcript at the time of CLL diagnosis, CLL was in remission at CML diagnosis, and CML was in complete cytogenetic response at AML onset, indicating that this was not a blast crisis. Background: Chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML) are the most common proliferative disorders in Western countries, with an incidence of 4.2/100,000/year and 1-1.5/100,000/year, respectively. The co-existence of both CML and CLL is an extremely rare event, even if it has been described in a few cases, either simultaneously or subsequently presenting. Above all, the presence of more than two different hematologic neoplasms has not been described in literature so far. In the present study we report a particular case of a CLL patient, who first developed CML and then acute myeloid leukemia (AML).