Objective: To evaluate the antifertility activity of hydroalcoholic extract of Delonix regia (Boj. ex Hook.) Raf. leaves and seeds which are traditionally being used by Yanadi tribe to treat dysmenorrhea. Methods: Three experimental animal models, including anti-implantation, early abortifacient, and estrogenic activity in female rats, were used for evaluation of the antifertility activity of both extracts at two dose levels (250 and 500 mg/kg, orally). There were five groups in the anti-implantation and early abortifacient activity while six groups in estrogenic activity including the standard. The number of implants, resorptions, vaginal cornification, body weight, uterus weight, and biochemical parameters were measured. Results: At doses 250 and 500 mg/kg, the leaf extract was found to have strong anti-implantation action. The extract administered at the same doses also caused a significant rise in the number of resorptions, showing early abortifacient activity, increased uterine weight, and altered numerous biochemical parameters. Meanwhile, the seed extract only displayed slight anti-implantation activity at both levels. Conclusions: Based on these preliminary findings, we can conclude that the leaf extract outperformed the seed extract in terms of antifertility activity, exhibiting potent estrogenic, anti-implantation and early abortifacient activities in a dose-dependent manner. These findings are consistent with the literature study and corroborate to the antifertility activity of the plant.