There are growing concerns about the decrease in male reproductive health and this has been associated with dietary factors (Sharma et al. 2013). The period of pregnancy is a susceptible period by which the fetus is exposed to such factors that may lead to unsuccessful reproductive functions (Bateson 2001), thus nutrition is an important factor for a successful pregnancy state. Fruits, seeds and nuts are essential in pregnancy. The seeds of papaya plant are eaten and used as medication in countries in Africa and Asia even in pregnancy. We have previously carried out studies to investigate the effect of the crude extract on pregnancy outcome and postnatal development. This study was to identify the fractions(s) from chloroform extract of Carica papaya seed and to evaluate the effect on in-utero exposure in male offspring.Gas Chromatography-Mass Spectroscopy (GCMS) of chloroform extract Carica papaya seed was carried out using standard methods. Pregnant rats (190-220g, n=25) were divided into three (first, second and third) trimesters as well as a precoital group and were continuously treated with 1000mg/kg of one of the purified compounds of CECS at 1000mg/kg, a no-observed-adverse effect level (NOAEL) according to the OECD guidelines (OECD, 2003) by oral gavage. The control group was administered olive oil the vehicle for oleic acid administration. Rats delivered naturally and pups were studied for post-natal variables from birth to puberty. Body weights, Anogenital Index (AGI) (using vernier caliper), somatic and pubertal landmarks were measured. Data were analyzed using descriptive statistics, ANOVA and Student’s t-test at p=0.05GCMS analysis yielded oleic acid (OA) (40.7%), cis-13-octadecenoic acid (27.9%), cis-vaccenic acid (20.7%), trans-13-octadecenoic acid (6.0%), n-hexadecanoic acid (2.4%) and tetradecanoic acid (1.8%). There was no mortality after OA treatment up to 2000mg/kg. Pregnancy outcome showed significant increase in gestation length of OA treated dams. Litter sizes in OA (5.5±0.9, 7.5±0.8, 5.5±0.9, 3.5±0.1) groups were significantly reduced when compared with the control (10.7±0.6). Body weight of offspring had alterations from birth to puberty. The AGI on post-natal day 4 significantly reduced in OA (1.9±0.0) offspring when compared with the control (2.3±0.1). Significant delay occurred in day of eye opening and fur appearance in the offspring. Puberty onset was significantly delayed in OA offspring. Continuous exposure of rat to oleic acid beginning from the second trimester showed foetotoxic effect.