Aim: The aim of this study is to study the effect of levothyroxine treatment on lipid profile in patients of subclinical hypothyroidism. Materials and methods: A randomized control trial, prospective study conducted on 22 cases of subclinical hypothyroidism with 22 control at the Downtown Hospital, Guwahati. Inclusion and exclusion criteria were undertaken. Levothyroxine therapy was given and was followed up after 3 months with thyroid and lipid profiles. Pretreatment and posttreatment values were compared using the paired t test using the statistical software SPPS v.19. Results: A statistical significance between pretreatment and posttreatment values is found to be in values of thyroid-stimulating hormone (TSH), cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglyceride (p < 0.05). There was no significant difference in the pretreatment and posttreatment T3 and T4 values. There was a mild increase in the value of HDL, a significant decrease in the value of TSH, cholesterol, very low-density lipoprotein (VLDL), and triglyceride. Conclusion: Lipid profiles are altered in patients with subclinical hypothyroidism compared to controls. Levothyroxine therapy has beneficial effect on lipid profile in patients with subclinical hypothyroidism.