The purpose of this study was to compare the effect of the McKenzie method of treatment with patient education in "mini back school" in patients with acute low-back pain. The study included 100 patients, 23 women and 77 men with the average age 34.4 +/- 9.7 (range 18-61) years. The study included only those who were employed. The patients were randomly allocated to two groups, one group receiving treatment according to the McKenzie technique and the other group receiving education in a "mini back school." Assessments were made after 3 weeks by an independent observer and after 52 weeks they were seen by one of the authors. Patients were assessed on seven variables: return to work, sick-leave during the initial episode, sick-leave during recurrences, recurrences of pain during the year of observation, patients' ability to self-help, pain and movement. Although the effect of attention placebo cannot be ruled out, the results demonstrated that the McKenzie method of treatment for patients with acute low-back pain was superior for five out of seven variables studied. The only variables that did not show any statistically significant differences were sick-leave during recurring episodes of pain and patients' ability to self-help.