The objective of the present experiment was to compare the effects of different maturation media on developmental capacity of in vitro fertilized bovine oocytes when co-cultured with bovine oviduct epithelial cells (BOEC) or cumulus cell monolayer (CCM). Oocytes aspirated from follicles of 2-5mm in diameter were divided into 4 groups and incubated for 22-24 h. Medium for control group was TCM 199 with 10% newborn calf serum (Control group). For the other groups, 30% follicular fluid (FF group), 10% estrus cow serum (ECS group) or 0.02 AU/ml of FSH and 1 μg/ml of estradiol-β(FSH/E2 group) were added to C group. Frozen-thawed semen treated with heparin and caffeine were used for ova insemination. Oocytes were placed on BOEC (n=572) or CCM co-culture (n=1,050) and cleavage rate and numbers of the stage of morula or blastocyst (morula/blastocyst stage) were recorded. The percentage of embryos cleaved were lower in ECS than in other groups (P<0.05)(27.5%, 27.9%, 18.2% and 23.9% for FF, FSH/E2, ECS and control group, respectively). Development to the morula/blastocyst stage was not different among groups (16.1 to 9.3%). Effect of co-culture with BOEC or CCM on cleavage and developmental capacity were not different (P>0.05). The proportion of morula/blastocyst from cleaved ova in FF and ECS groups were significantly higher than FSH/E2 and control groups (P<0.01). Fifteen blastocyst were transferred to 15 heifers and two recipients were confirmed pregant at day 30 and 90, and finally 2 male calves were born. The production of 2 calves from in vitro matured, fertilized and developed embryos was first success in Uruguay. These results indicate that certain biological fluids such as FF and ECS induce successful maturation of bovine follicular oocytes in vitro and that resulting embryos can be successfully cultured on either BOEC or CCM.