Besides their role in making energy, polyunsaturated fatty acids can affect on ovarian ollicles and corpus luteum by providing the precursors required for the synthesis of gnaling molecules such as steroids and prostaglandins. The effects of α-linolenic acid ALA) on developmental competence of oocytes in goats were evaluated in this study. nitially, ALA content of follicular fluid of small and large follicles was determined using C–mass chromatography. Our results indicated that the ALA concentration was in a range 64.6 to 100.6 μM for small and large follicles, respectively. Then, based on preliminary sults, goat oocytes were matured in presence of 0 (Control), 10 (ALA-10), 50 (ALA-50), 100 (ALA-100)and 200 (ALA-200)μM of ALA. Twenty four hours after in vitro aturation (IVM), oocytes in each group were evaluated for their cumulus cell expansion nd also for their maturation rate. Furthermore, matured oocytes were treated for parthenogenetic activation and the cleavage and blastocyst rates of control and ALA-treated oup were recorded at day 3 and 8 post-activation. Data from each stage were recorded nd analyzed via Compare Means Test and/or chi-square analysis using SAS software. upplementation of maturation media with different concentration of ALA had no effect on umulus cell expansion except in the highest concentration (ALA-200)that decreased the umulus cell expansion (P˂0.05). Our findings indicated that maturation rate was higher P˂0.05)in ALA-50 group as compared with the control group (68.1% vs. 58.2%). Moreover, supplementation of maturation medium with 50 μM ALA improved the cleavage te (65.2% vs. 52.8%) and blastocyst rate (25.1% vs. 16.7%)as compared with the control oup (P˂0.05). Collectively, our results showed that treatment of maturation medium with optimum concentration of ALA had a beneficial effect on oocyte maturation by increasing he maturation rate and this in turn, can stimulate the embryonic development. 1- M.Sc. Student, Pardis Aboreyhan of T