Trichonodosis(knotted hair) is a disorder of the hair shaft that can comprise a single or double knot. Reports of trichonodosis are not cornmon in dermatological literature, but it is generally considered not to be rare. Two varieties of trichonodosis have been described. A rare type occurs in association with abnormally growing scalp and body hair that tends to splinter and fracture. A more comrnon form occurs when normal hair is subjected to rnechanical forces, such as combing and brushing. Trichonodosis occurs exclusively in persons with curly or kinky hair. We report a patient with short, straight hair and trichonodosis. The most likely cause in our patient is trauma as a result of continual rubbing of hairs. (Korean J Dermatol 1997;35(6): 1241-1243)