ABSTRACT The current study aimed to assess the efficacy of two unlike laser wavelengths (655 nm and 808 nm) used as photobiomodulation or low-level laser therapy (LLLT) on the immune status in male rats. Sixty-five male Sprague–Dawley rats were considered in the experiments which were further divided into three groups. For all the three groups, LPS (lipopolysaccharide) was used as an immunostimulant and it was administered 5mg/kg via intraperitonially (ip) route for 3 consecutive days. In the first group, 655 nm LLLT (power 150 mW) was investigated against LPS induced immune response. Second group investigated 808 nm LLLT (power 150 mW) against LPS induced immune function. After finding out the better responsive LLLT, third group investigated 808 nm LLLT with different power ie 75 mW and 150 mW. The results indicated that 655 nm LLLT at 150 mW power was not restored LPS associated TNF-α and IL-1β content. While, LPS induced enhance IL-1β and TNF-α level was significantly decreased in 808 nm LLLT group. Further, comparison was studied in 808 nm LLLT at different power ie 150 mW and 75 mW and pro-inflammatory cytokines estimation was quantified. The outcome of the study concluded that 808 nm LLLT has anti-inflammatory activity at 150 mW power. Hence, the further research work is required in this direction to advise that 808 nm LLLT at 150 mW could be considered as a treatment to protect inflammatory diseases. Keywords: Photobiomodulation; low-level laser therapy (LLLT); immune status; 655nm; 808nm; in vivo