Common variable immunodeficiency (CVID) is a primary immunodeficiency disease characterized by hypogammaglobulinemia and recurrent bacterial infections. The records of 65 patients with CVID (37 males and 28 females) in the age range of 24 to 537 months were reviewed. By the year 2003, 11 patients had died and seven patients could not be located. The total follow-up period was 221 patient-years. The median diagnostic delay (time between onset and diagnosis) in our patient group was 60 months. At the time of diagnosis, the baseline serum immunoglobulin G (IgG), IgM, and IgA levels were below the level normal for the patients' age; the medians for this group were 120, 10, and 0 mg/dl, respectively. All of the patients presented with infectious diseases at the time of onset, the most common of which were otitis media, diarrhea, pneumonia, and sinusitis. Acute and recurrent infections were also found in almost all of the patients, particularly involving respiratory and gastrointestinal systems. The most common infections, before diagnosis and during follow-up, were pneumonia, acute diarrhea, acute sinusitis, and otitis media. CVID should be considered in any patient with a history of recurrent infections and decreased levels of all serum immunoglobulin isotypes.