Leukocyte adhesion deficiency type I (LAD I) is a rare, inherited, autosomal recessive, immunodeficiency disease caused by the combined loss of expression on the surface of leukocytes of the leukocyte integrins. We describe the clinical and laboratory findings for 15 patients with LAD I. The range of patients' ages was from 10 month to 14 years (median 4 years) and 93.3% of their parents had consanguineous marriages. The most commonly occurred manifestations were: recurrent infections (93.3%), poor wound healing (86%), oral ulcers (86%), and skin abscesses (80%). The most specific laboratory findings were defect in CD18 in all of 15 patients. The most common symptoms in these patients are poor wound healing and oral ulcer, so, the clinical physicians should pay special attention to these symptoms. Furthermore, because of considerable rate of consanguineous marriages in parents of LAD patients, we suggested more genetic studies on this disease and genetic consultation for these families.