The object of the study was to describe socioeconomic and demographic determinants of inpatient hospital care for lumbar intervertebral disc disorders (LIDD) in Finland. Information from the 1996 Finnish Hospital Discharge Register was linked with the 1995 Population Census. Poisson regression analyses were made with the total and the gainfully employed workforce aged 20-64 y as reference. All 48 public and seven private acute care general hospitals treating LIDD patients in Finland. In the workforce, 4643 patients aged 20-64 y (3692 among the gainfully employed) were admitted to the hospital due to LIDD (ICD-10: M51.1-M51.9) in 1996. About one-half were treated surgically. The duration of unemployment in 1995 was inversely associated with hospitalisation for LIDD in 1996, allowing for age, sex, education and personal income (unemployed for 12 months vs 0 months: rate ratio 0.66; 95% CI 0.57-0.77). Among those employed for 12 months in 1995, the level of education was inversely associated with the hospital admission rate. The rate was also higher in manual occupations as compared with the upper white-collar employees. The associations were clearer among the medically than the surgically treated patients. Hospitalisation for back disorder was, however, less common in the lowest income group as compared with the highest (0.65; 0.57-0.77) allowing for education, occupational class, age and sex. Women were less often admitted to the hospital than men, allowing for the socioeconomic factors (0.83; 0.77-0.90). When indicated by education or occupation, low socioeconomic status was associated with a relatively high rate of inpatient hospital care for LIDD. When indicated by personal income, the situation was the reverse. Unemployment and female gender predicted a relatively low rate of hospitalisation.