The evaluation of testicular function is based primarily on a detailed medical history, a careful physical examination, basal measurements of FSH, LH and testosterone and a routine semen analysis. In a patient with androgen deficiency, the diagnosis can often be made with these basic tests. The clinician will then decide on other investigations to localize the organic lesion and to plan further treatment for the patient. Sperm function tests are often performed in patients presenting with infertility. These newer tests may help to delineate the abnormality of the spermatozoa at each stage during the achievement of fertilizing capacity such as adequate forward motility, penetration of cervical mucus, acrosome reaction, development of hyperactivated motility, binding to the zona pellucida, and fusion with the oocyte. Currently, many of these sperm function tests depend on cumbersome bioassays with many limiting factors contributing to their availability, accuracy and precision. The development of biochemical tests as markers of sperm function may allow more precise definition of sperm functional abnormalities. With the continued improvement of computer-aided sperm analysis, objective motion parameter measurements are possible and morphological assessment are being developed. These newer objective methods of semen analysis have to be shown to be valuable in the clinical assessment of patients with testicular dysfunction.