Este artículo debe citarse como: Cambray-Gutiérrez JC, Herrera-Sánchez DA, Blancas-Galicia L, O'FarrillRomanillos PM. Clínica de inmunodeficiencias primarias en adultos. Experiencia en un hospital de tercer nivel. AbstractBackground: Primary immunodeficiencies (PID) are characterized by alteration of the components of the immune system. Humoral deficiencies represent 50%. The most common are selective IgA deficiency, Bruton agammaglobulinemia, and common variable immunodeficiency (CVID). Objective: To describe the epidemiological and clinical characteristics of adults with humoral PID, cared for in a Primary Humoral Immunodeficiencies Clinic. Methods: A descriptive cross-sectional study that included a year of analysis, including 35 patients with humoral PID, 31 with CVID, and 4 with Bruton agammaglobulinemia. Data were analyzed with descriptive statistics. Results: Of 35 patients studied, 31 had CVID (88.5%) and 4 (11.5%) Bruton agammaglobulinemia; 21 were men and 14 women. The age at onset of symptoms was 22.7 years, and the delay in diagnosis was 7.2 years. 11.4% of CVID patients died during the study; 4 had malignancies, 22.8% autoimmune diseases, and 48.5% gastrointestinal disorders. Patients with Bruton agammaglobulinemia presented no comorbidities. Conclusions: Unlike reports in the literature, in the study group, CVID was the most common cause of humoral PID, predominantly in men; the most common gastrointestinal disorder was intestinal functional disorder.