| Common variable immune deficiency (CVID) is a heterogeneous syndrome characterized by hypogammaglobulinemia, recurrent infections, immune disregularity (autoimmunity, autoinflamation) and propensity to malignancies. In the US report, 8.2% of CVID patients had a lymphoid malignancy, and cancers of other sorts developed in 7% of patients. It is not clear why CVID patients have higher risk of malignancy but chronic antigenic stimulation, chronic inflammation and increased chromosomal radiosensitivity may be the cause. CVID patients with higher IgM level, reduced or absent B cell numbers, CD4 T cells lower than 200 and PLI phenotype have higher prevalence of malignancy. Allergy and clinical immunology department of Rasool E Akram hospital has registered 47 CVID patients. Mean age of the onset of CVID symptoms was 11.2 years. Mean diagnosis age was 20.2 years with mean diagnostic delay of 9 years. Mean follow up time was 7 years (minimum 0.5-maximum 23 y). Malignancy occurred in the follow up of 6 patients (13%). One patient had two different malignancies (breast cancer and GI adenocarcinoma). Malignancy risk per case was 15%. Hodgkin’s lymphoma was the most common type (43% of cancers).Other cancers include: Breast cancer, gastrointestinal cancer, Leukemia and CNS cancer. Malignancy is one of the main complications of CVID. It is necessary to monitor |