Researchers aimed at ascertaining if and how low-level (LLLT) or high-intensity laser therapy (HILT) combined with rehabilitation exercise (LLLT + E or HILT + E) affects pain, stiffness and function in knee osteoarthritis (KOA). They searched five databases (PubMed, Web of Science, CINAHL, PEDro and SPORTDiscus) resulting in retrieval of 10 studies, six investigating LLLT + E, three HILT + E, and one evaluating both. Findings suggest that in the management of KOA, both LLLT and HILT are beneficial as adjuncts to rehabilitation exercise. An indirect comparison seems to suggest higher efficacy of the HILT + E in lowering knee pain and stiffness and in improving function. A direct investigation that compares the two types of laser therapy may be needed.