We report a retrospective study of 209 patients presenting with alopecia areata (AA) at our skin department during the period 1969-1987, with special reference to possible associations, aetiological factors and the relevance of additional investigations. The patients were divided into two groups: (I) those in whom AA developed during childhood; (II) those in whom AA developed in adult life (greater than or equal to 16 years). The aim of this study was to establish whether there is a difference between juvenile and maturity-onset AA and to consider the value of additional investigations in AA. Juvenile AA is more severe and has a less favourable prognosis than the maturity-onset disease. Statistically significant differences between the two groups were not found with respect to AA type and prevalence of auto-antibodies. Bad prognostic signs in AA were early age of onset, atopy (or first-degree family history) and ophiasis and/or onychodystrophy. Initial thyroid function testing seems advisable in patients with AA. Additional valuable investigations may include hair-root examination, determination of antibodies against thyroid tissue, and serum zinc levels. There are indications that psychosomatic factors may play a role in AA. In our study, psychosomatic factors were found in 29% of the juvenile AA and in 17% of the maturity-onset AA patients.