Leishmaniasis is still a problem for many countries including developed ones. The subgroups of the serum complements have significant roles on the onset of the infection. The aim of this study was to determine the serum complement (C1, C3, C4) levels of cases with definite diagnosis of leishmaniasis and compare them with healthy controls. The study group included 43 visceral leishmaniasis (VL) and 13 cutaneous leishmaniasis (CL) cases. Two control groups were formed for the study. The first control group included 50 individuals of the same age group having no health complaints, admitted for routine control and found to be serologically negative. The second control group included 28 individuals, consistent with the diagnostic criteria of VL. The serum complement levels of C1, C3 and C4 were measured by the nephelometric method. The average levels of C1 were found to be high in VL cases (78.98%) and low in CL (41.69%) group, which was statistically significant (p=0.011). In addition, the average levels of C3 were high in CL group (96.08%) and low in VL group (62.00%), which was also statistically significant (p=0.010). C4 levels were found to be high in the control group, while similar in VL and CL groups. C1, C3, C4 levels were found to be lower in the first control group of healthy individuals. The levels of the subgroups of complement system show statistically significant in both VL and CL cases, which suggested that they could be useful in verifying the results of the serological examinations.