We verify the efficiency of a protocol for estrus synchronization in captive female collared peccaries (Pecaricari tajacu) using the prostaglandin analog D-cloprostenol. Five adult female collared peccaries received an intramuscular administration of 60 µg D-cloprostenol, which procedure was repeated after a 9-day interval. For 10 days after second the D-cloprostenol administration, females were monitored for changes in external genitalia, ovarian ultrasonography, vaginal cytology and reproductive hormonal dosage. As a result, four females synchronized their estrous at 9.5 ± 0.5 days after the second administration of the prostaglandin analog. Such females showed external signs of estrus, including vulvar opening, hyperemic vaginal mucosa, and vaginal mucus, concomitant with an increase in the proportion of superficial cells (52.2 ± 9.9%) verified through vaginal cytology. An estrogen peak of 22.7 ± 3.4 pg/ml was detected by hormonal dosage, and the presence of anechoic follicles measuring 0.29 ± 0.05 × 0.32 ± 0.07 mm were detected in the ovary by ultrasonography. Given these findings, we suggest that D-cloprostenol may be effective for use in estrus synchronization in collared peccaries.