The Klinefelter syndrome is most common chromosomal cause of male infertility. However, the many cases of the syndrome remain undiagnosed due to variations in clinical presentation. A patient attended to surgical OPD with complaints of loss of secondary sexual characteristics and infertility. Physical examination revealed tall stature, thin built, small testes size, and absence of beard and pubic hairs. Karyotype and biochemical tests were performed to detect chromosomal abnormality as well hormonal level to confirm the diagnosis of androgen deficiency syndrome. Chromosomal complement confirmed the case of Klinefelter syndrome (47, XXY) causing androgen deficiency. Timely detection of Klinefelter syndrome is important to formulate further treatment modalities for the benefit of the patient.