To evaluate the efficacy and safety of topical 0.005% tacrolimus eye drop for treatment of refractory vernal keratoconjunctivitis (VKC). This prospective study included 20 eyes of 10 patients with refractory VKC, who had active symptomatic disease despite conventional medications including topical steroids. After discontinuing all other medications, patients were treated with topical 0.005% tacrolimus eye drop four times a day. Changes in subjective symptoms and objective signs after treatment were evaluated, and development of possible complications was assessed. Mean age of patients was 21.3±7.4 years and mean duration of VKC was 12.1±5.8 years. After starting tacrolimus eye drop, patients were followed for a mean duration of 10.7±3.7 months (range, 6-15 months). All symptoms including itching, redness, photosensitivity, foreign body sensation, and mucus discharge improved after the treatment; itching was the first symptom to show dramatic relief. In addition, there was improvement in objective signs including conjunctival hyperaemia, conjunctival papillary hypertrophy, giant papillae, limbal hypertrophy, corneal punctate epithelial erosions, and corneal pannus; conjunctival hyperaemia was the first sign to show improvement. No patient required addition of other medications including steroids for further relief. Any attempt to discontinue tacrolimus eye drop was associated with recurrence of patients' symptoms and signs, necessitating continued use of the medication during the entire follow-up time. No ocular complication related to tacrolimus was noted. Topical 0.005% tacrolimus eye drop seemed to be a safe and effective treatment for steroid-resistant refractory VKC; however, long-term use was needed to control the disease.