This study was done on 110 patients with different types of malignant diseases and 20 healthy controls. Cases were divided into four groups according to parasitological and serological examination. The first group included 37 patients without any parasitic infection, the second 28 patients with no opportunistic parasitic infection, the third group 33 patients with opportunistic parasitic infection while the fourth included 12 patients with mixed opportunistic and non opportunistic parasites. Immunological status was estimated by carrying out leucocyte migration inhibition test and intradermal skin test for cell mediated immunity and quantitative determination of immunoglobulins IgG, IgM and IgA for humoral immunity testing. It was found that cell mediated immunity was decreased in cancer patients compared with the normal control group. Super added parasitic infections lead to greater decrease. Opportunistic parasitic infection aggravated the condition more. Marked suppression of the cell mediated immunity was found in the group of cancer patients with mixed opportunistic and non opportunistic parasitic infections. IgG and IgA were increased in the first three groups and decreased in the mixed one, IgM was increased in the first and second groups while decreased in groups with opportunistic infections.