We investigated the effect of minimal essential medium (MEM), coconut water solution (CWS), and MEM supplemented with CWS on viability, activation, and growth of ovine primordial follicles. Ovarian cortical slices were cultured in vitro for 1, 3, or 5 days in MEM, CWS, or MEM supplemented with 5, 10, 20, 50, 80, 90, or 95% CWS. Both MEM and CWS were supplemented with FCS, ITS, glutamine, pyruvate, and hypoxanthine. Before (Day 0) and after 1, 3, or 5 days of in vitro culture, follicles were isolated from the ovarian tissue, and their diameters were measured as well as evaluated by using trypan blue staining. Based on the uptake or not of trypan blue, follicles were classified as viable or nonviable, respectively. Follicles were also classified as primordial or developing based on their morphology. The results showed a reduction (P < 0.05) in viable follicles after 1 day of culture compared to uncultured controls with the exception of MEM supplemented with up to 20% CWS. After 5 days of culture, significantly higher percentages of viable follicles were observed in MEM and MEM plus 5% CWS. A percentages of developing follicles increased significantly after culturing cortical tissue for 5 days in MEM or MEM plus 5 or 10% CWS. In all media tested, a significant increase in follicle diameter was observed after 5 days of culture with MEM only or MEM with 10% CWS. In conclusion, sheep primordial follicles are successfully activated in vitro after culture in MEM alone or with 5 or 10% CWS.