The aim was to assess the self-efficacy and health outcomes of an adopted Arthritis Self-Management Programme (ASMP) among osteoarthritic knee sufferers in Hong Kong at 1 year. An experimental study with 95 participants assigned randomly to the intervention (n=45) or control group (n=50). Seventy-seven (81.1%) participants joined at least one out of three follow-ups in the 12 month period. Participants in the intervention group received a 6-week ASMP with an added exercise component in two general clinics. Outcome measures included arthritis self-efficacy (ASE) and health outcomes including pain and fatigue rating, self-rated health, daily activities limitation and number of unplanned arthritis-related medical consultations. Mean change (12 months minus baseline) and the effect size of the outcome measures were calculated by Mann-Whitney U test and nQuery Advisor 4.0. At 12 months, there were significant reductions of current pain (p=0.0001), pain at night (p=0.001), pain during walking (p=0.01) and number of unplanned arthritis-related medical consultations (p=0.03) and a significant increase in ASE for pain (p=0.01) and other symptoms (p=0.02) and self-rated health (p=0.04) among the intervention group but not for the control group. However, there were similarities in outcome measures of pain while switching from a sitting to a standing position, fatigue rating and physical functional limitation (p=0.15; p=0.22 and p=0.91, respectively) for both groups. Our findings add to the evidence that the modified arthritis empowering programme improved perception of control of osteoarthritis and three health outcomes after 12 months of treatment.