Toward evidence-based policy decisions: a case study of nursing health human resources in Ontario, Canada This paper reflects how health services research 'evidence' was used to influence decisions in the province of Ontario, Canada. The process involved interaction among a variety of stakeholders and decision-makers with researchers to reduce uncertainty and to substantiate emerging service provision issues in the province. The issues presented here focus specifically on an analysis of the nursing situation completed in 1998 for the Minister of Health's Nursing Task Force, which examined key issues in service delivery. The issues were: restructured work environments; nurse supply and declining enrollments; labour trends and utilization of the nursing workforce; patient acuity and complexity of work environments and the influence on workload; and the paucity of reliable and valid data bases for analysis of nursing's contribution to the health system. Ontarians can be confident that the Task Force recommendations were born from solid research-based evidence and now the challenge becomes to monitor the implementation of these resolutions over time.