Longitudinal melanonychia (LM) is a brown-black pigmented band extending from the matrix up to the distal part of the nail plate, normally induced by melanocyte activation, lentigines, nevi, and malignant melanomas.1 Exogenous pigments can also cause melanonychia, but they usually do not form regular linear bands. Herein, we report a case of childhood LM caused by exogenous pigmentation.