Abstract background: platelet-rich plasma (prp) and ozone therapy have been proposed as therapeutically efficient agents for the management of pain in knee osteoarthritis (koa). aim of the work: to reveal the efficiency of intra-articular injection of prp and ozone therapy in the treatment of patients with primary koa compared to a basic rehabilitation program. patients and methods: 60 patients with koa were randomly classified into 3 groups (20 patients each); group i received intra-articular prp injection, group ii received ozone and group iii performed a rehabilitation program. all patients were assessed by visual analogue scale (vas), western ontario and mcmaster universities osteoarthritis index (womac) and 6-min walk test at baseline and after 1 and 3 months. results: the patients mean age was 55 ± 4.5 years and were 46 females: 14 males (f:m 29:3). the age and gender were comparable among the 3 groups. there was high significant difference between prp and others 2 groups as regard vas after 1 and 3 months treatment (p < 0.001) while there was insignificant difference between groups ii and iii after one month from treatment; but there was significant difference between them at three months. after treatment regarding womac score there was a significant difference between studied groups after 1 and 3 months of treatment (p < 0.05) while there was an insignificant difference between groups regarding 6 min–walk test after 1 and 3 months. conclusion: the use of autologous prp is an efficient treatment of koa and resulted in better outcomes than ozone therapy up to 3 months. publishing services provided by elsevier b.v. on behalf of egyptian society of rheumatic diseases.