The aim of an ergonomics intervention conducted in the tire manufacturing industry was to improve working conditions. Before the start, a senior manager supported the intervention. Participants were divided into teams and trained. After observing the overall performance of the teams, over 100 improvements were successfully implemented. After the improvements, there were statistically significant differences in annual and weekly prevalence of, and annual disability reported for, the upper back, the lower back, knees and wrists between before and after intervention. The annual prevalence of upper back, lower back, knee and wrist complaints decreased from, respectively, 60.3%, 50.2%, 28.9%, 25.8% before the intervention to 31.3%, 35.9%, 17.1%, 20.7% after the intervention. Significant factors were training and supportive environment based on full commitment of the top management.