Orlistat is medication used to treat obesity. This research aim investigation how of relationship between orlistat treatment use and thyroid hormone levels. Thyroid hormones of obese of male albino rat have been studied. In addition, little is understand about how losing weight changes thyroid operation. Thus, we researched more about the thyroid hormone status and potential effect of weight loss on thyroid hormones. We study of 32 male albino rat obese with mean age 12 weeks. The animal divide to four groups and all group included Of these 8 animals. The first group is control, second group (120 mg /kg / day), third group (180 mg /kg / day) and forth group (240 mg /kg /day) for 12 weeks of treatment. The results showed had significant decrease (P ≤ 0.05) T4 level in Group 3 (8.041± 0.016) and group 4 (1.400±0.972) compared with control 31.600±0.0258 ng /ml. and total T3 level in Group 3 and 4 significantly decrease P ≤ 0.05) 6.233 ± 0.145; 0.340±0.021 compared with control 12.641±0.203) ng /ml, (P ≤ 0.05); while TSH level in Group 3,4 (2.491± 0.485, 5.243±0.673) had significant increase (P ≤ 0.05) compared to those of control without orlistat drug 0.691±0.057 uIU/ml and other groups. Obesity condition may effect thyroid hormone levels. beyond lowering body weight, orlistat may have varied effects on thyroid hormone status.