Background: Alopecia areata is an immunologically mediated cessation of hair growth primarily involving, but not limited to, the scalp. The treatment of alopecia areata involves promotion of hair growth (for instance with topical minoxidil application), immunosuppression (intralesional or systemic steroid therapy, phototherapy) or immunomodulation (anthralin, dinitrochlorobenzene, diphenylcyclopropenone, squaric acid dibutylester). All these medications have some disadvantages and difficulties for the treatment of children with alopecia areata. Objective: To use an open-pilot study to assess the efficacy of topical 1% sildenafil in children diagnosed with alopecia areata. Methods: Eight patients with (<= 25% of scalp surface area involvement) alopecia areata who were refractory to previous topical treatments applied 1% sildenafil twice daily for 3 months. All the patients completed the study. Results: Two patients experienced vellus-type hair growth and one patient had terminal hair growth. However, these outcomes were accepted as the spontaneous regression of the disease. Conclusion: We cannot recommend the use of topical 1% sildenafil for the treatment of alopecia areata without further evidence of its therapeutic benefit.