A retrospective study of adult-onset laryngeal papilloma was performed to clarify whether any clinical features at the time of diagnosis could predict its course. All patients had a histologically confirmed diagnosis of laryngeal papillomas and were treated at Helsinki University Hospital between 1975 and 1994. Those with adult-onset disease and follow-up exceeding 1 year (n = 74) entered the study. Based on the case records surveyed, results suggested two risk factors for frequent laryngeal procedures: young age at onset of papilloma and a lesion extending to the anterior third to the vocal folds. It was not possible to predict the course of the disease by such clinical findings as symptoms or size or number of primary papilloma lesions. As regards the recurrence of disease, the classic division of adult-onset laryngeal papilloma into solitary and multiple type was not found to be clinically relevant.