Distinguishing leukemic phases of B-cell disorders in peripheral blood smears is well recognized to be difficult in some cases since it depends on subtle and subjective criteria. In order to quantify cytological features and to assess objective descriptions, a morphometric analysis was performed on 83 peripheral blood smears of B-cells disorders (n = 77) and healthy donors (n = 6). Using standardized May-Grunwald Giemsa staining, standardized image acquisition system and well defined microscopic fields, we have analyzed lymphoid cells, measuring morphometric and color parameters. By combining seven relevant morphometric criteria (the nuclear shape, the cellular shape and area, the nucleo-cytoplasmic ratio, the nuclear red/blue ratio, the cytoplasmic green/blue ratio and the proportion of cells with nucleolus), we have established a score that could range from a minimum of -3 (large B-CLL type) to a maximum of +8 (large MCL type): negative scores corresponds to different types of B-CLL (n = 30), including "atypical B-CLL" (n = 6), the score zero correspond to healthy donors (n = 6) used as baseline, the positive score values correspond to +1 for Follicular lymphoma (n = 2), +3 for Splenic Lymphoma with Villous Lymphocytes (n = 12), +4 for Hairy Cell Leukemia (n = 7), for Hairy Cell Leukemia-variant (n = 2), +6 for B-prolymphocytic leukemia (n = 6) and +7 and +8 for most Mantle Cell Lymphoma (n = 18). Testing T-cell disorders samples (n = 10) using the same protocol, the profile is different and cannot be confused with B-cell diseases. Our scoring system indicates that measurement of some common morphologic features in standardized conditions provides objective criteria to characterize those diseases and might be helpful for diagnosis.