This Working Paper analyses the impact of IMF stabilisation programmes in developing countries. Three different kinds of test can be applied to assess the impact of Fund programmes. First, actual economic performance during and immediately after the programme can be compared with performance immediately before it. Second, comparing actual results with programme targets. Third, and in principle the most attractive test, comparing programme results with what would have occurred in the absence of the programme. Using these methods, the paper concludes that, even though the results are complex, the overall impact of the programmes was slight. Part III of the paper summarises the reasons for this disappointing outcome.