Abstract: This study was carried out to investigate the impact of oral administration of chloroform extract of Carica papaya seed (CPE) on implantation and pregnancy in female albino rats. The study was divided into three experimental sections. Each section was subdivided into 4 groups treated, respectively with 25, 50 and 100 mg kg-1 b.w CPE and 2.5% tween 80 in normal saline (vehicle for CPE; control). Rats in section 1 were treated with CPE for two weeks before mating (pre-coital). Rats in section 2 were administered CPE from day 1 of pregnancy till term (post coital) while rats in section 3 received the extract for two weeks before mating and thereafter throughout term (pre and post-coital). Implantation sites and resorptions were determined in some of the pregnant rats after laparotomy. The gestation period, litter size and fetal weight were recorded in the remaining rats. The litters were also observed for any morphological alterations. The extract treated rats had significant decreases in litter size and implantation count (p<0.01). The percentage resorptions increased in a dose dependent manner while the fetal weight and morphology remain unchanged when compared with the normal untreated control groups. The percentage resorptions were high in CPE treated rats when compared with the control group. None of the 100 mg kg-1 b.w CPE treated female rats had litters. The results suggest that the chloroform extract of Carica papaya seed has anti-implantation and abortifacient properties in female albino rats.