The present patient presented with true leukonychia in association with Crohn disease as well as selenium deficiency. Although there have been some reports about associations of leukonychia, Crohn disease, and selenium deficiency, all 3 conditions have not been discussed together. An association of Crohn disease with half-and-half nails has been reported in at least 1 case,2 but the serum selenium levels were not estimated in that case. Furthermore, Crohn disease has been associated with selenium deficiency,3 but the nail conditions were not described in detail in those reports. Therefore, we believe this case to be the first providing evidence that true leukonychia is caused in part, if not wholly, by selenium deficiency in Crohn disease and is curable with selenium substitution. However, care must be taken with adverse effects,4 and selenium levels must be carefully monitored to avoid toxic effects.