The aim of this study was to determine whether the application of intramuscular progesterone induces estrus activity in anovulatory Dorper sheep exposed to the male effect. A total of 20 ewes diagnosed as anovulatory, were divided into 3 homogeneous groups in terms of weight and body condition. Ewes had no contact with males at least 3 weeks before exposure to the male. While a group of ewes (G1; n = 6) received a single dose of 20 mg i.m. progesterone (day −2 of breeding), a second group (G2; n = 7) received a single dose of 40 mg i.m. of progesterone (day −2 of breeding), and the third group (GE n = 7) were inserted with a intravaginal sponge with 20 mg of progesterone (day −6 breeding) which was removed one day before introduction of the male. This experimental breeding was performed with males previously treated daily with testosterone (25 mg i.m.) during 15-d before mating to induce an intense sexual activity. Three males (one per group) were rotated every 12 h among experimental groups. Estrus activity was evaluated twice daily 1 h during 15-d. On d-12 after male introduction, an ultrasonographic scanning was performed to determine the percentage of ovulated females. Percentage of ewes depicting estrus and ovarian activity were compared using chi2, using the program SYSTAT 12. While no females from the G1 group expressed estrus activity (0/6, P < 0.05), all ewes of both the G2 and GE showed estrus activity (P > 0.05). In addition, most of the females from all the experimental groups depicted ovulatory activity (G1 5/6; G2 5/7 and GE 7/7 P > 0.05). The application of 40 mg i.m. of progesterone before the male effect was demonstrated to be as effective as the traditional use of intravaginal sponges to induce estrus response and ovulation in previously anovulatory females exposed to the male effect. Yet, the use of i.m. progesterone is significantly cheaper and easier to apply.