Swaziland has the highest national incidence of tuberculosis (TB) in the world, with treatment success rates well below the 85% international target. Treatment support as part of comprehensive TB services is a core component of the Stop TB Strategy. This study investigated the effects of financial incentives for treatment supporters on TB treatment outcomes in Swaziland. This was a controlled study that compared treatment outcomes for patients with a treatment supporter who received or did not receive a financial incentive. This research is supported by the Department for International Development’s COMDIS–HSD Programme which is led by the University of Leeds