The aim of this study was to determine the effects of FSH and LH hormones on in vitro development of cat oocytes. The ovaries from spayed cats were brought to the laboratory in +4degreesC PBS solution two hours after being collected. The oocytes were recovered by slicing of ovaries and were separated into two groups: Group 1 (Control); TCM 199 + 5% FCS + 2.2 g/l NaHCO3 + 0.23 mM Na Pyruvate: and Group 2 (Treatment): TCM 199 + 5% FCS + 2.2 g/l NaHCO3 + 0.23mM Na Pyruvate + FSH (Sigma F-2293) (1 mug/ml) + LH (Sigma L-5269) (1 mug/ml). Oocytes were matured for 48 hours at 38.5degreesC and 5% CO2 in a humidified atmosphere. At the end of this period oocytes were fixed, stained and evaluated for maturation criteria by phase-contrast microscope at x400 magnification. Data were analyzed statistically by Student's t-test.