A total of 17 patients with yellow nail syndrome are described. Their symptoms, age of onset and severity are examined with particular reference to the presence of rhinosinusitis. Fourteen of the patients (83%) suffered severe rhinosinusitis, which pre-dated nail changes in four, coincided with yellow nails in six, and occurred later in the remaining patients. In general, patients responded poorly to conventional medical and surgical treatment, with the exception of functional endoscopic sinus surgery (FESS) which may be of value in these patients. The frequent association of rhinosinusitis with yellow nails may warrant its recognition as part of the syndrome. Careful inspection of the fingernails in all patients presenting with severe rhinosinusitis is warranted.