Transient Hypogammaglobulinemia of Infancy (THI) is an uncommon disease entity in which the exact incidence, definition, etiology and outcome remain to be unknown. Affected individuals may be asymptomatic or may have increased frequency of infections. We are reporting a 5 year old boy with dysmorphic features, double left ureter, supravalvular stenosis, laryngotracheobronchomalacia, seizure disorder and multiple serious bacterial infections. The patient had Pneumococcal meningitis at age 7 months and two episodes of Klebsiella sepsis at age 7 weeks and 8 months. He was born full term via spontaneous vaginal delivery with ABO incompatibility for which he received exchange transfusion. Family history is unremarkable. Significant findings in the physical examination included large anterior fontanelle, hypertelorism, downslanted palpebral fissures, bilateral pre-auricular sinuses and wide-shaped, pointed teeth. Laboratory evaluation showed low serum immunoglobulins. Antibodies to tetanus and diptheria toxoids and hemophilus influenza b were present. Lymphocyte subsets, as well as, lymphocyte proliferative response to PHA, con-A and pokeweed mitogens were within normal limits for age. Serum complement levels and nitroblue tetrazolium test (NBT) were also normal. Delayed type hypersensitivity testing with PPD, candida and tetanus remained negative. Cytogenetic studies failed to detect any chromosomal abnormality. HIV testing was negative. The patient was followed closely in Immunology clinic. He did not develop any subsequent problems except for mild upper respiratory tract infections which were managed symptomatically. At 5 years of age, the patient's panhypogammaglobulinemia resolved.