Purpose: To determine the prevalence of systemic atopy and immunoglobulin (Ig) deficiencies in vernal keratoconjunctivitis (VKC). Methods: Sixty-seven VKC subjects (79.1% boys) with a mean age of 11.3±4.3 years were included. Serum Ig levels and specific IgE levels were measured using the nephelometric method and reversed enzyme immunoassay with sandwich ELISA technique, respectively. The patients underwent epidermal skin tests with commercial extracts. Results: Family history of atopy and associated systemic allergies were detected in 32.8 and 40.3% of the subjects, respectively. Blood eosinophilia, elevated total, and specific IgE and positive skin tests were detected in 33.8, 42.2, 50, and 35% of the subjects, respectively. Out of 62 subjects, low levels of IgA, IgG, IgM, and IgG3 were detected in 12.9, 8, 6.5, and 1.6% of the patients, respectively. Conclusion: IgE-mediated mechanisms are involved in approximately 40% of VKC patients. A new finding was the higher incidence of Ig deficiency. © 2013 Informa Healthcare USA, Inc.