BackgroundIn a participatory approach to health and development interventions, defining and measuring community mobilisation is important, but it is challenging to do this effectively, especially at scale.MethodsA cross-sectional, participatory monitoring tool was administered in 2008–2009 and 2009–2010 across a representative sample of 25 community-based groups (CBGs) formed under the Avahan India AIDS Initiative, to assess their progress in mobilisation, and to inform efforts to strengthen the groups and make them sustainable. The survey used a weighted index to capture both qualitative and quantitative data in numeric form. The index permitted broad, as well as highly detailed, analysis of community mobilisation, relevant at the level of individual groups, as well as state-wide and across the whole programme.ResultsThe survey demonstrated that leadership and programme management were the strongest areas among the CBGs, confirming the programme's investment in these areas. Discussion of the Round 1 results led to efforts to strengthen governance and democratic decision making in the groups, and progress was reflected in the Round 2 survey results. CBG engagement with state authorities to gain rights and entitlements and securing the long-term financial stability of groups remain a challenge.ConclusionThe survey has proven useful for informing the managers of programmes about what is happening on the ground, and it has opened spaces for discussion within community groups about the nature of leadership, decision making and their goals, which is leading to accelerated progress. The tool provided useful data to manage community mobilisation in Avahan.