Objective: To investigate how worksite health interventions involving a 2.5-hour reduction of weekly working hours with (PE) or without (RWH) mandatory physical exercise affects productivity. Methods: Six workplaces in dental health care were matched and randomized to three conditions (PE, RWH and referents). Employees' (N = 177) self-rated productivity and the workplaces' production levels (number of patients) were examined longitudinally. Results: Number of treated patients increased in all conditions during the intervention year. While RWH showed the largest increase in this measure, PE showed significant increases in self-rated productivity, that is, increased quantity of work and work-ability and decreased sickness absence. Conclusions: A reduction in work hours may be used for health promotion activities with sustained or improved production levels, suggesting an increased productivity since the same, or higher, production level can be achieved with lesser resources.