An increase in the serum copper (Cu++) level has been described as a sensitive index of disease activity in several hematologic and nonhematologic malignancies. In order to explore the diagnostic value of Cu++ compared to other hematochemical parameters frequently abnormal in malignancies, Cu++, serum alpha2 globulin (alpha2), plasmatic fibrinogen (Fibr), the erythrocyte sedimentation rate (ESR), and serum iron (Fe++) have been detected and evaluated in 267 patients affected with the following diseases: Hodgkin's lymphoma (HL), non-Hodgkin's Lymphomas (NHL), Acute Leukemias (AL), Chronic Myeloid Leukemia (CML), Chronic Lymphocytic Leukemia (CLL), Myeloma (MM), and Breast Cancer (BC). The best correlation between Cu++ increase and disease activity has been found in HL, NHL, AL, and BC. In these diseases, when the considered parameters were compared, Cu++ and ESR showed a similar pattern, i.e., a high frequency of abnormalities in active disease. It is concluded that Cu++ represents a good complement to some other aspecific parameters in evaluating the activity and diffusion of neoplasias and the therapeutic results, particularly in HL, NHL, AL and BC.