ABSTRACT: BACKGROUND: People with rheumatoid arthritis (RA) suffer increased risk of disability and premature mortality. Health-enhancing physical activity (HEPA) could be one important factor to reduce this risk. Rising health care costs call for the development and evaluation of new modes of rehabilitation, including physical activity in settings outside the health care system. METHODS: This cohort study targets 450 patients with RA that do not currently meet HEPA recommendations, recruited from six hospitals reporting to the Swedish Rheumatology Quality Registers (SRQ). We have developed a two-year real-life intervention program including a minimum of twice-weekly circuit training, moderately intense physical activity the remaining days of the week and group meetings to support behavior change every other week. Our hypothesis is that increased physical activity and exercise will improve perceived health, reduce pain and fatigue, increase muscle function and aerobic capacity, impact psychosocial factors and prevent future cardiovascular events. Research questions regard outcomes, retention rates, dose-response matters and the exploration of responder characteristics. This protocol outlines recruitment procedure, design, assessment methods and the intervention program of the study. DISCUSSION: The PARA 2010 project is designed to expand the knowledge on HEPA in RA by a progressive approach regarding population, setting, intervention, time frames and outcome measures. To our knowledge this is the first long-term HEPA program based on Social Cognitive Theory, and performed in a real life environment to demonstrate if this new setting can promote increased and maintained physical activity in people with RA. Trial registration number ISRCTN25539102.