Split-thickness skin grafting (STSG) is widely used to heal wounds resulting from trauma, burns, and chronic wounds. This study aimed to determine the true effect of platelet-rich fibrin (PRF) on patients with burn wounds requiring STSG during treatment of donor wounds. This randomized, triple-blind clinical trial was conducted on patients who referred to the burn ward of Vasei Hospital of Sabzevar, Iran, from May 2017 to May 2018. The donor site was randomly divided into 2 groups: PRF and control (Vaseline petrolatum gauze) using Vaseline gauze. In the intervention group, the PRF gel was applied to the wound and covered with Vaseline gauze and wet dressing. Conversely, only Vaseline gauze and wet dressing were applied to the control group. Outcome evaluation was conducted using paired t test and Wilcoxon signed rank-sum test, as appropriate, on days 8 and 15. The mean age of the patients was 33.10 ± 2.60 years, and 51.50% were male. The mean wound healing time in the PRF and control groups was 11.80 ± 3.51 and 16.30 ± 4.32 days, respectively (P < .001). The PRF group showed significantly higher wound healing rates than the control group at 8 and 15 days dressing (P < .001 and P < .001, respectively). Moreover, the mean wound healing for all wound healing indices diagnosed by 2 specialists in PRF was higher than control group on days 8 and 15 (P < .001). We found a statistically significant difference on days 8 and 15 regarding the mean pain levels between the 2 groups (P < .001). The findings showed that PRF can significantly increase the time and rate of donor wound healing compared with conventional treatment and also reduce the severity of pain.