This trial was conducted to determine the effect of sunflower cake on the physicochemical properties of meat lamb. Forty crossbreed Santa Ines rams were fed 50% hay (Tifton-85 chopped) to 50% concentrate (corn, soybean meal, urea, ammonium sulfate and inclusion of sunflower cake) on diet. The 4 treatment diets were 0, 10, 20, and 30% sunflower cake. To account for the increasing concentration of sunflower cake, corn and soybean meal were removed from the diet. The rams were fed the treatment diets twice daily for a period of 71 d in feedlot, and were slaughtered after that. After a period 24 h postmortem, the Longissimus dorsi muscle were removed of carcass, separated into proximal and distal portions. The muscles from the distal portion’s left side were used to determine the pH and color measurements with Minolta colorimeter and pH probe. The muscles from proximal portion the right side were used to measure the cooking loss and Warner-Bratzler shear force analysis was conducted according to the guidelines of AMSA. The experiment followed a completely randomized design with 4 treatments and 10 replicates per treatment. The data were analyzed using PROC GLM procedure of SAS (SAS Institute, Cary NC) with the treatments as the fixed effect. Regardless of inclusion rate, sunflower cake did not have an effect on pH (P = 0.15), L* (P = 0.28), cooking loss (P = 0.23), shear force (P = 0.47). There was an effect on color a* (P = 0.03) and b* (P = 0.04) with increasing concentration of sunflower cake, that characterizing bright cherry red color meats. Many factors (endogenous and exogenous) can contribute to meat color stability as pH, muscle source and mitochondrial activity, as well as live animal related factors, such as management, diet, and genetics. The competition between mitochondria and myoglobin (Mb) is a key component in the development of bright-red color. Probably occurred saturation Mb with oxygen forming oxymyoglobin or saturation Mb with carbon monoxide, forming carboxymyoglobin that offer bright cherry-red color meat. The sunflower cake inclusion has provided bright redder color meat without changing the cooking loss and tenderness of meat.