Protein electrophoresis and immunoelectrophoresis carried out on 4805 sera and 93 urine samples from Tunisian patients over 8 years, and a monoclonal protein was detected in 198 cases. The distribution of the monoclonal compounds to the clinical diagnosis was studied. 115 (58%) were classified as multiple myeloma (MK), 34 (17%) as alpha heavy chain disease (MCL a), 34 (17%) as monoclonal gammapathy associated to various diseases (GMOD), 11 (6%) as benign essential monoclonal gammapathies (GMBE), 4 (2%) as Waldenström's macroglobulinemia (MW). The relationship between the monoclonal immunoglobulin and the clinical diagnosis, the distribution of the monoclonal compounds according to the heavy chain class and the identification of the light chains were studied. The results obtained are in line with the principal data in literature concerning monoclonal gammapathy. However there is a particularity about monoclonal gammapathy observed in the Tunisian's population studied: Higher percentage of alpha heavy chain diseases, monoclonal IgD and monoclonal light chain. Lower percentage of monoclonal IgM in GMBE or GMOD, as in MW.