This study describes the anti-heat stress benefits of Seleni-um-enriched probiotics (SP). A total of 200 1-d-old male broi-ler-chickens were subjected to heat stress due to natural high ambient temperature of summer. The broilers were randomly categorized into 4 treatments with 5 replicates per treatment and 10-broiler-chickens per replicate. They were fed a basal control diet (Con) and basal diet with probiotics (Pr), sodi-um-selenite (SS), and SP for 42 days. Se concentration/kg of diet for Con, Pr, SS, and SP groups was 0.10, 0.11, 0.41, and 0.44 mg/kg, respectively. The birds were graded for % age-la-meness and body weight gain (BWG). The blood samples and bone marrows were collected after 42 days and analyzed through radioimmunoassay, rt-PCR, and atomic fluorescent spectrophotometer. It was found that the BWG was improved with no lameness in SP group. SP decreased serum oxidati-ve markers, malondialdehyde, and T4 and increased Ca and P levels, T3, glutathione peroxidase, superoxide dismutase, and catalase (p<0.05). Furthermore, the SP treatment upregulated the mRNA expression of DIO2 and MCT-8, whereas downre-gulated DIO3. It concludes that SP as a feed additive with Se concentration of approximately 0.4 mg/kg improves growth performance and lameness by improving skeletal system th-rough the upregulation of DIO2 and T3 in heat-stressed broilers.