In order to investigate the effect of inorganic selenium replacement with organic selenium from Spirulina algae on PERFORMANCE and breast meat quality of broilers, a total of 160 one-day-old chicks were used in a completely randomized design with four treatments, eight replicates and five birds per each replicate. The sources of selenium used included sodium selenite and organic selenium from Spirulina algae which were replaced at two levels of 50 and 100 percent. The organic selenium was produced by the culture of Spirulina algae and its enrichment with selenium. The selenium content of different treatments was measured by ICP-Mass method. In this experiment, the feed intake and body weight gain parameters were measured weekly and feed conversion ratio was calculated. At 42 day of age, one bird was slaughtered from each replicate and the weight of carcass ready to cook was measured. The breast meat was sampled for measurement of pH and selenium storage. The results showed that it was not observed any significant difference in PERFORMANCE traits and ready to cook carcass percentage among different treatments. There was no significant difference in breast muscle pH at 0 and 24 hours after slaughtering. The amount of selenium deposited in breast muscle of birds fed organic selenium had significant increase when compared with other treatments (P<0.05). Generally, the results of this study showed that 100% replacement of sodium selenite with organic selenium from Spirulina algae led to increase in breast muscle selenium deposition without reduction in bird PERFORMANCE.