The aim of this study was to determine the effect of Methyl-B-Cyclodextrin (MBCD) on capacitation of buffalo sperm. Frozen/thawed semen was incubated in the absence of capacitating agents (negative control), in the presence of 10 µg/ml heparin (positive control) and of 1, 2, 4 and 8 mg/ml MBCD for 2 and 4h. At each incubation time, sperm motility was evaluated by phase contrast microscopy. Capacitation was assessed by the sperm ability to undergo acrosome reaction after lysophosphatidylcholine treatment, evaluated with viability by Trypan blue-Giemsa. After 2 h capacitation increased (P