We assessed the prevalence of nail abnormalities in 272 children with alopecia areata who were seen in our department during an eight-year period. Of these, 126 (46%; 50 girls, 76 boys) had nail abnormalities that were related to alopecia areata. Nail pitting was detected in 92 patients, including 37 with alopecia totalis or alopecia universalis. Three patients experienced an onychomadesis of all 20 nails during the acute onset of alopecia areata universalis. Thirty-two (11.7%) had nail thinning and severe nail plate surface abnormalities that were consistent with a diagnosis of trachyonychia.