We describe the value of three scoring systems for the characterisation of haemopoietic malignancies. One of the scorings was devised to disclose unusual cases of biphenotypic/mixed lineage acute leukemias and proved to be useful to distinguish such cases from those ALL or AML with aberrant expression of one or two markers of another lineage. The other two scorings aimed respectively: 1) to discriminate between B-CLL from all other B-cell disorders which evolve with leukemia and 2) distinguish between hairy cell leukaemia (HCL), HCL-variant and splenic lymphoma with villous lymphocytes, a group of B-cell diseases with circulating "hairy" lymphocytes. Findings derived from the application of the latter two scoring systems in a large number of cases demonstrated that both provide objective criteria to differentiate between the B-cell conditions studied and that no single marker considered in isolation allows the distinction between the various B-lymphoproliferative disorders.