BACKGROUND: OECD countries over the past two decades have implemented a range of labour market integration initiatives to improve the employment chances of disabled and chronically ill individuals. This article presents a systematic review and evidence synthesis on effectiveness of government interventions to influence employers' employment practices concerning disabled and chronically ill individuals in five OECD countries. A separate paper reports on interventions to influence the behaviour of employees. METHODS: Electronic and grey literature searches to identify all empirical studies reporting employment effects and/or process evaluations of government policies aimed at changing the behaviour of employers conducted between 1990 and 2008 from Canada, Denmark, Norway, Sweden and the UK. RESULTS: Few studies provided robust evaluations of the programmes or their differential effects and selection of participants into programmes may distort the findings of even controlled studies. A population-level effect of legislation to combat discrimination by employers could not be detected. Workplace adjustments had positive impacts on employment, but low uptake. Financial incentives such as wage subsidies can work if they are sufficiently generous. Involving employers in return-to-work planning can reduce subsequent sick leave and be appreciated by employees, but this policy has not been taken up with the level of intensity that is likely to make a difference. Some interventions favour the more advantaged disabled people and those closer to the labour market. CONCLUSIONS: Future evaluations need to pay more attention to differential impact of interventions, degree of take-up, non-stigmatizing implementation and wider policy context in each country.