Two experiments were conducted to evaluate the use of various levels of full-fat sunflower seeds (FFSS) on broiler performance and carcass characteristics. In the first experiment, FFSS was included in a basal diet at 70, 140, and 210 g/kg and the AME(n) values of the experimental diets were determined. The linear regression equation of AME(n) values on rate of inclusion was calculated. Extrapolation value for the AME(n) of FFSS at 100% inclusion was 14.22 MJ/kg. In the second experiment, diets containing various levels (0, 70, 140, and 210 g/kg) of FFSS were given to broilers (Ross strain) from 0 to 49 d. At 28 days of age, blood parameters and digestive enzyme activities were determined and carcass parameters were evaluated at 49 days of age. Weight gain, feed intake and feed conversion ratio (FCR) were improved (p<0.05) when broilers were fed various levels of FFSS in the starter and finisher diets. Breast, thigh, gastrointestinal tract and gizzard weight percentages were not affected by dietary treatments; however, liver weight percentage was decreased significantly (p<0.05) and weight of abdominal fat decreased but this effect was not significant. The activities of digestive enzyme (protease and a-amylase) were not influenced by the treatments. Activity of alkaline phosphatase, concentrations of calcium, phosphorus, glucose, triglyceride, protein, high density lipoprotein (HDL) and low density lipoprotein (LDL) were not affected by incorporation of FFSS in the broiler diet. Although concentration of HDL increased and LDL decreased, these effects were not significant. The results of this study indicate that FFSS can be used at up to 2 1% in broiler diets without adverse effects on performance or other parameters of chickens.