The present study was carried out to study the effect of Spirulina supplementation on the growth and some physiological performances of the Gimmizah males exposed to heat stress (HS). A total number of 150 male 4 weeks old Gimmizah were randomly allocated in five groups (3 replicates, 10 chicks each). The first (positive control, PC) was reared under 22-24OC and PH 45-55% and fed unsupplied basal diet, B). Whereas, the other groups were reused under HS (38°C±1; 55-65 % RH) for three successive days /wk from 11.00 a.m until 15.00 p.m, through the experimental period (4 to 14 wks of age) in a battery brooders. The first HS group was used as a negative control (NC) and fed B. The 3rd and 4rd groups fed B plus 250 and 150 mg Spirulina /kg diet, respectively. The 5 group was fed the B plus 75 mg VE /kg diet. The feed consumption was significantly decreased for all groups under HS compared with PC group, while FCR for the groups under HS (supplied with Spirulina or VE) were significantly improved compared with NC. The differential of leukocytic count for the NC group recorded the significant increase on Lymphocyte, Heterophil and the ratio of H/L compared with other groups. The concentration of globulin and activity of GSH-PX were significantly improved for the groups supplied with both levels of Spirolina under HS compared with the NC group. The highest Infections Bronchitis titer was recorded for the group supplied with VE and PC group. In conclusion, addition of 150 and 250 mg Spirulina platensis /kg diet improved performance, immunity and can be decreased the adverse effect of heat stress for Gimmizah mail during growing period (4-14 wks of age).