Abstract : The research included estimation of orexin-A level in coronary heart patients and compared it with control group. The results demonstrate that the normal mean of orexin A in serum control group was (344. 47± 6.51 pg/mol) for both sexes and ages range between (20-more of 50) year and there was a significant decline in orexin A level in patients compared to control group. Also, orexin A level was not affected by age and sex. Obese and overweight individuals have significant decrease in hormone level than the normal and underweight. The clinical parameter showed a significant decrease in adiponectin and HDL-C concentration in patients compared to control group. While there was a significant increase in insulin, glucose, total cholesterol, triglyceride concentration, HOMA-IR and atherogenic index in patients compared to control. Study the correlation coefficients of orexin A with some clinical parameters showed a significant negative correlation of orexin A with glucose, total cholesterol, triglyceride concentration and atherogenic index in control and patients group and with insulin and HOMA-IR in patients. Also, there was a significant positive correlation with concentration of adiponectin and HDL-C in control and patients group and with insulin in control group. It was concluded that Orexin A has a protective effect against CHD and low level of Orexin A increases risk of CHD. Moreover, there is a relation between orexin A and obesity, orexin A protect against obesity, and the level of orexin A could be used as a marker for CHD and obesity