In 67 cases of newly diagnosed blood malignacies, NonT-ALL, T-ALL, AMLL, AML, CML, CLL, HCL, PLL, MDS, B splenic lymphoma, AUL, as well as in 9 cell lines (U937, HEL, Jurkat, HL60, UHKT2, KG1, Raji, K562, REH), we have analysed the expression and distribution of 2 relatively incompletely studied antigenic markers from the CD nomenclature: CDw12 and CD17, individually and in combination with well characterized ones. We present our data for the usefulness of these molecules in immunodiagnosis of leukemias and lymphomas.