Lobster-claw deformity of the extremities, clefting of the primary and secondary palate, ectodermal dysplasia, and atresia of the lacrimal system are common features of the ectrodactyly-ectodermal dysplasia-clefting syndrome (EEC-syndrome). The patients often suffer from repeated infections of eyes, upper respiratory tract and urogenital system. To exclude an immunodeficiency as cause of the infectious predisposition in patients with EEC-syndrome, we screened the immunosystem in four related patients with EEC-syndrome. All patients were found to present normal immunoglobulin production, complement activity, lymphocyte-, and granulocyte function. We conclude that recurrent infections observed in the EEC-syndrome are not caused by an immunological defect, but seem to result solely from anatomical anomalies.