Purpose: the purpose of this study was to assess the efficacy of PRP prolotherapy in patients with symptomatic TMJ hypermobility after single versus double sessions of PRP injections.Patients and methods: Thirty-eight patients with bilateral TMJ hypermobility were included in this study. They were 11 males and 27 females. Their ages ranged from 18- 45 years, with an average of 28.43 ± 6.92 years. In group 1, each TMJ received single session of intra-articular and pericapsular injections with 1.5 ml of PRP. While in group 2, each TMJ received two sessions of injection with 2 weeks apart. Clinical outcomes including pain severity on function, according to the visual analog scale (VAS), frequency of luxations, maximal mouth opening (MMO) and clicking sound were measured at baseline and at 6, 12 and 30 weeks after treatment.Results: Both groups showed statistically significant decrease in all the evaluated parameters at the first follow-up interval that maintained thereafter. By the end of the present study, the comparison between the two groups showed significant decrease in pain scores, frequency of luxation and MMO in group 2 compared to group 1.Conclusion: The results of the present study reveal the short-term effectiveness of PRP prolotherapy with double dose of PRP is more effective to alleviate symptoms of TMJ hypermobility than single dose.