Tacalcitol is a vitamin D analog with proven efficacy for the topical treatment of psoriasis, but to date it has not been tested in psoriasis of the nail. However, successful treatment has been reported with other vitamin D derivatives such as topical calcipotriol, and topical calcitriol in one study. The present study aimed to assess the efficacy and tolerability of topical tacalcitol in the treatment of nail psoriasis in a sample of 15 patients over a 6-month period. Treatment with tacalcitol ointment may be useful to treat nail psoriasis as it achieves a significant improvement in all nail parameters, both of the matrix and of the bed.