SummaryBackgroundCytokeratins (CK) belong to the family of intermediate filament proteins, and among them specific epithelial keratins are considered markers for stem cells activation.ObjectivesThis study aims to investigate the expression of CK15 and CK19 as possible stem cell markers in vitiligo during phototherapy.MethodsThe study was conducted on vitiligo patients receiving narrow‐band ultraviolet therapy. Immunohistochemical staining for CK15 and CK19 was carried out, and clinical follow‐up continued for 4 weeks.ResultsOf 28 patients, CK15 expression was demonstrated in 17 cases (61%) while CK19 expression was demonstrated in 11 cases (39%). Cells expressing positive staining were demonstrated in follicular and interfollicular epithelium. Expression was clearly demonstrated in patients younger than 20 years old, with shorter disease duration, with disease stability, and with normally pigmented hairs. Expression of cytokeratins was significantly correlated to improvement of vitiligo lesions.ConclusionCK15 and CK19 are expressed in vitiligo during UV repigmentation in the follicular and interfollicular epithelium. This expression of cytokeratins was significantly correlated to improvement and can be considered valuable tool to monitor stem cells stimulation for the sake of the repigmentation process in vitiligo.