Introduction: Thyroid hormones have significant functions in embryogenesis and fetal development. Evidence suggests that thyroid stimulating hormone (TSH) may exert extra-thyroidal effects and modify the profile of blood lipids. Aim: To determine the association between maternal blood lipid profile and thyroid stimulating hormone in second and third trimester of pregnancy. Methods & Materials: The present study was carried out at MGM Hospital, Navi Mumbai, India. 200 antenatal cases from October, 2012 to October 2014 were enrolled after taking an informed consent. The blood samples for Thyroid stimulating hormone and lipid profile were taken at 16th and 32nd weeks. Results: The mean TSH level in second trimester was 1.53 mIU/L, with a standard deviation of 1.147 mIU/L. In third trimester, the mean TSH level was increased to 2.60 mIU/L with a standard deviation of 0.836mIU/L. The t-stat value was found to be -10.649 (p < 0.001). In third trimester, TSH was negatively correlated with Cholesterol (r= -0.214, p < 0.01) and VLDL (r= -0.148, p < 0.05). Conclusion: TSH levels rises according to the gestational age, being higher in third trimester as compared to second trimester. There is a significant negative correlation between TSH levels and cholesterol & VLDL in third trimester of the pregnancy. Hence, TSH levels should be looked for, especially in third trimester, in order to keep the thyroid related problems in check. Keywords: TSH, Lipid Profile, Pregnancy.