The aim of this study was to determine the effects of the administration time of misoprostol (11 h (Miso11) and 6 h (Miso6) before artificial insemination) on fertility rates in Kivircik ewes (control: n = 41, Miso11: n = 32 and Miso6: n = 33) during breeding season. Artificial insemination (AI) was performed 48 h after sponge removal using frozen-thawed semen (150 million sperm per dose in 0.25 ml straws). Estrus synchronization parameters (onset and duration) and lambing rate were evaluated. No significant difference was observed among groups for the estrus onset and duration hours (P > 0.05). The lambing rates in the control, Miso11 and Miso6 groups were 39.0, 62.5 and 54.5%, respectively. There were significant differences among the control, Miso11 and Miso6 groups according to lambing rates (P < 0.05). In conclusion, misoprostol treatment significantly improved fertility in ewes when using frozen-thawed semen in AI. Administration of misoprostol 11 h before AI resulted in a higher lambing rate than that at 6 h before AI; therefore, treatment of misoprostol 11 h before AI can effectively be used.