Objective: This study was undertaken due to the popular belief in most of the Asian countries that the unripe fruit of Carica papaya L if eaten during early months of pregnancy can lead to miscarriage. The aim of the present study was to screen the effect of administration of hydroethanolic extract of unripe fruit of Carica papaya L (EECP). Materials and Methods: Female pregnant rats were taken and divided into various groups viz; GroupI (control); GroupII (200mg/kg po EECP); GroupII (400mg/kg po EECP; and Group IV (Ethinyl estradiol 0.02 mg/kg. po) for the experiments. After oral administration of the extract laparotomy was performed and uteri were examined to determine the number of implantation sites. At the end of the experiment all the rats in each group were sacrificed. Haematological and biochemical parameters were determined. Hormone level modulation was also analyzed. Results: The present study suggested that there are significant variations in the biochemical parameters. The hormonal stability had also been altered which had in turn led to the termination of pregnancy. Conclusion: The study revealed that hydroethanolic extract inhibited the process of implantation. The loss of implantation caused may be due to antizygotic, blastocytotoxicity of the extract.