The success of infertility treatments like intrauterine insemination, in vitro fertilization and intracytoplasmic sperm injection are mainly dependent on the sperm motility, its ability to undergo capacitation and acrosome reaction etc. Most of the infertile men have a poor sperm function. In such cases enhancing their ability by treating with any agents under in vitro conditions certainly helps in increasing the chances of conception. Earlier studies have shown that pharmacological agents like pentoxifylline, caffeine and 2-deoxy adenosine can improve the function of spermatozoa in vitro. However, due to their deleterious effect on early embryo development, their application is limited. This study aims at improving the sperm function of infertile men by supplementing a B-complex vitamin, biotin, during sperm preparations. Since biotin is an essential micronutrient required for normal development and highly water soluble, it can be a safe agent. The present investigation is an attempt to analyze whether biotin can enhance the sperm function of infertile men and what is its mechanism of action. (Supported by Indian Council of Medical Research, Govt. of India)