Short-term whole safflower seed supplementation was evaluated in anestrous ewes. Ewes were synchronized using a 7 d progestagen-based protocol during the non-breeding season. Safflower seed supplementation did not improve estrus, pregnancy, lambing rate, or litter size. Serum estradiol increased and PGFM (13,14-dihydro-15-keto prostaglandin F2α) decreased over time in both experimental groups. Whole safflower seed cannot be recommended as a short-term nutritional adjunct for improving out-of-season reproductive performance in ewes.