Monilethrix is a hereditary hair disorder that occurs monosymptomatically or as a monilethrix syndrome combined with other ectodermal anomalies. We report two siblings with the triple combination of monilethrix, keratosis pilaris, and koilonychia. In one of our patients, the hair disorder improved, with maximum hair growth up to 8 cm in length after her first menstrual period occurred, suggesting that hormonal influences may improve the hair disorders in monilethrix.