Most of the carcass fat and the saturated ones in particular, have a great effect in raising blood cholesterol concentration, which contributes to the process of coronary atherosclerosis, the main cause of coronary heart disease. In most cases, the lesions attract platelets and fibrin which block the coronary artery and cause ischemia. The consumer has been aware of the health problems associated with consuming the broiler chickens, carcass fat, and so a demand for leaner birds. Accordingly, the poultry industry has been faced with the problem of producing leaner birds and reducing fat deposition in the broiler carcasses in order to meet the consumer demand. At the research level, many scientists have investigated ways of decreasing abdominal and broiler carcass fat deposition. These authors established that fat accretion is governed by the genetic constitution of the bird, and is closely influenced by the nutritional and management practices, in addition to the effect of environmental temperature, sex, and age. However, many scientistsstated that most influencing agent is the dietary factors (energy, protein level, source and quality respectively, energy to protein ratio and feeding system. In this reviewed paper author compared dietary different sources, level and quality inclusion in broiler diets studied by many scientists and stated that dietary fat sources significantly increased broiler performance, serum and carcass lipids and altered fatty acids concentration and type in all levels and quality with exceptions for high level vegetable oils inclusion (6% and more) which significantly decreased broiler performance and all serum carcass traits.