Abstract Background: Narrowband ultraviolet B (NB-UVB) phototherapy is the cornerstone of vitiligo treatment. Its combination with other treatments usually yields a better response. Latanoprost, a prostaglandin F2α analog, and autologous platelet-rich plasma (PRP) have been reported to be effective for vitiligo. Aim: To evaluate the efficacy of NB-UVB combined with intralesional latanoprost or PRP for stable nonsegmental vitiligo (NSV). Methods: Sixty patients with stable NSV were recruited and randomly allocated to two equal groups. NB-UVB phototherapy was administered twice a week for all patients. Additionally, group A received intralesional latanoprost injections once weekly, while group B received intralesional autologous PRP injections every 2 weeks. Results: At 24 weeks, excellent repigmentation response was observed in 26.7% and 13.3% of patients in the latanoprost/NB-UVB and PRP/NB-UVB groups, respectively, with no significant difference in degrees of repigmentation between the two groups. However, the Vitiligo Extent Score for a Target Area (VESTA) score was significantly higher in the latanoprost/NB-UVB group (p = .032). Moreover, lesions located on nonacral skin responded significantly better than those on acral skin. Only erythema was significantly higher in the PRP/NB-UVB group, while the recurrence of depigmentation was significantly higher in the latanoprost/NB-UVB group. Conclusions: Both latanoprost and PRP have the potential to be effective add-on therapies to NB-UVB phototherapy for stable NSV, with latanoprost resulting in a greater repigmentation response and PRP producing a more stable response.