Objective: To examine the association between DDT (dichlorodiphenyl trichloroethane) and HCH (hexachlorocyclohexane) exposure and intrauterine growth retardation (IUGR, <10th percentile of birth weight for gestational age). Method: We detected p,p¢-DDT, o,p¢-DDT, p,p¢-DDD, p,p¢-DDE and a-HCH, b-HCH, c-HCH, d-HCH in maternal blood, placenta and cord blood, collected at parturition, from mothers with IUGR babies (n=30) and from those with babies of normal weight (n=24), using gas-liquid chromatography equipped with electron capture detector ( 63 Ni). The adjusted odds ratios (ORs) for these pesticides in mothers and infants were determined by multiple logistic regression. Results: There were statistically significant associations (P<0.05) between maternal blood levels of a-HCH (OR=1.22; 95% CI: 1.02-1.46), c-HCH (OR=1.38; 95%CI: 1.05-1.80), d-HCH (OR=1.61; 95% CI: 1.01-2.54), total HCH (OR=1.07; 95% CI: 1.01-1.13) and p,p¢-DDE (OR=1.21; 95%CI:1.03-1.42) and IUGR after adjustment for potential confounders. Also, significant association (P<0.05) between cord blood levels of c-HCH (OR=1.14; 95% CI: 1.00-1.31), d-HCH (OR=1.31; 95% CI: 1.00-1.75), total HCH (OR=1.07; 95% CI: 1.00-1.14) and IUGR were found after adjustment for potential confounders. A significant negative correlation between body weight of newborn babies and p,p¢-DDE in maternal blood (r= -0.25; P<0.05) and d-HCH and p,p¢-DDE in the cord blood (r= -0.27 and -0.26; P<0.05) was noticed after gestational age had been accounted for. Conclusion: Exposure of pregnant women to organochlorine pesticides may increase the risk of IUGR, which is a contributing factor for infant mortality in India.