A total of 103 young men in compulsory military service, diagnosed and treated for neurotic illness, were studied on the basis of medical and social background data, follow-up and personal re-examination to investigate prognostic factors in neurotic illness. Functional capacity was used as a criterion of neurotic disability, and 55 76 of the patients had no 'functional failure' during the average observation period of 10.7 years.Factors having a positive prognostic significance were: no psychiatric disorders in the immediate family, a good emotional environment in childhood, neither very strict nor unstructured upbringing, ability for social adjustment during adolescence, a harmonious marriage during the observation period and fitness for military service at follow-up. Factors indicating high level of education and high social class did not affect long-term prognosis, nor did mental capacity.Good social adjustment in adolescence has a positive effect on later functional capacity, and might be a more reliable prognostic evaluator than ordinary clinical personality assessment. A harmonious marriage provides a sense of specific security essential to the neurotic's capacity to function adequately in society. The ability to adjust to military service in spite of neurotic disorders has a high degree of correlation to a good civilian prognosis. The fact that education and social class did not affect prognosis might be an indication that factors traditionally regarded as predisposing to psychiatric illness are becoming less significant.K e y zeords. Functional capacitysocial adjustmentmilitary service fitnesssecurity in marriageneurotic disorderspredisposing factors.