Last few decades have revolutionized medical practice with advancement in biomedical field. This especially applies on finding innovative non-surgical approaches to different medical pathologies. Laser came into existence in 1960’s. Usage of Laser got its population with varying degree of applications in medical sciences. The modern use of laser has spanned from skin treatment to surgical procedures. Modern medical science is continuously expanding its horizons to explore the utilization of laser in different pathologies. Osteoarthritis is one of the major debilitating, progressive, degenerative musculoskeletal condition in the world affecting millions of people worldwide. Medical science has been exploring different avenues to treat this pathology with as non-invasive means as possible. Low level laser therapy (LLLT) has been investigated and used in various musculoskeletal conditions for last two decades including knee osteoarthritis. Different search engines and terms were used to find relevant articles. Inclusion and exclusion criteria were set to select the articles. This review looked at different evidences to see how LLLT is effective in treating the knee osteoarthritis and what challenges still exist in LLLT application to treat knee osteoarthritis. Looking at different existing researches, LLLT has mixed results on knee OA. Evidences depict positive outcomes of LLLT and yet do not show significant results. LLLT can show beneficial outcomes but different factors could impact those results. Evidences should focus on different aspects of LLLT in knee OA.