Common variable immunodeficiency is the most frequent of the primary hypogammaglobulinemias. It is manifested by a wide variety of clinical signs and symptoms. In this retrospective, nationwide survey data were collected on all patients with common variable immunodeficiency who were receiving immunoglobulin replacement therapy in Finland to study the prediagnostic clinical picture, diagnostic delay, and diagnostic findings. Ninety-five patients were identified. The median age of the patients was 33 years. Sixteen of the patients were children. Sinopulmonary infections were the most common prediagnostic signs and symptoms; 66% had suffered from recurrent pneumonia, 60% from recurrent maxillary sinusitis, and 45% from recurrent bronchitis. There was a considerable delay in diagnosis. The mean delay was 8 years. At the time of diagnosis chronic pulmonary complications had already developed in 17% of the patients. The diagnosis was based on low serum immunoglobulin concentrations. This study showed that the awareness of common variable immunodeficiency is low. To improve the recognition of hypogammaglobulinemia, it should be suspected in every patient with recurrent bacterial infections. In addition to a low serum IgG concentration, measurement of specific antibody production is recommended to establish the diagnosis before initiation of a life-long and costly replacement therapy.