Abstract. The need for effective global monitoring of biodiversity is clearer than ever, but our measurements remain patchy and inadequate. In the biodiversity-rich tropics, a central problem is the sustainability of monitoring schemes. Locally-based, participatory approaches show promise in overcoming this problem, but may not contribute effectively to monitoring at larger scales. BirdLife International's framework for monitoring Important Bird Areas (IBAs) in Africa is designed to be simple, robust and locally-grounded, but to produce scaleable results that can be compiled into national or regional indices. Focusing on key sites for bird conservation, identified according to standard criteria, the framework institutionalises monitoring in site management authorities and Site Support Groups (community-based organisations of local people working for conservation and sustainable development). A small, central monitoring unit co-ordinates the programme nationally, compiles, analyses and manages data, and provides feedback. 'Basic' monitoring (taking place at all sites) involves scoring of state, pressure and response trends using site information submitted on simple forms. 'Detailed' monitoring (taking place at a selected sub-set of sites) involves more intensive measurement of particular variables that relate to site management targets. IBA monitoring is now underway in at least 10 African countries, with implementation of the framework most advanced (thanks to a pilot project) in Kenya. The 2004 IBA monitoring report for Kenya provides extensive information on individual IBAs, plus indices for national trends in state, pressure and response, based on data from 49 out of 60 sites. The experience in Kenya shows that institutionalisation is vital, but takes considerable time and effort; that adequate co-ordination (including timely feedback) is key; and that participatory monitoring has many valuable benefits beyond the data collected. Further work is being undertaken to refine the process, improve its scientific underpinning, and strengthen the feedback loop from data and analysis to action on the ground.