BACKGROUND: Occupational health and safety (OHS) information is often complex, diverse and unstructured and suffers from a lack of integration which usually precludes any systemic insight of the situation. AIMS: To analyse to what extent the use of geographical information systems (GISs) can help to integrate, analyse and present OHS data in a comprehensive and communicable way relevant for surveillance purposes. METHODS: We first developed a 'macro-approach' (from national to local level), mapping data related to economic activity (denominator of active workers displayed by activity sectors), as well as work-related ill-health (numerators of workers suffering from work-related ill-health). The latter data are composed of compensated occupational diseases on the one hand and work-related diseases investigated by specialized clinics on the other hand. Then, a 'micro-approach' was worked out, integrating at a plant level, using computer-aided drawing, occupational risks data and OHS surveillance data (e.g. use of medication and sickness absence data). RESULTS: At the macro-level, microelectronics companies and workers were mapped at different scales. For the first time, we were able to compare, up to the enterprise level, complementary data showing different pictures of work-related ill-health, allowing a better understanding of OH issues in this sector. At the micro-level, new information arose from the integration of risk assessment data and medical data. CONCLUSIONS: This work illustrates to what extent GIS is a promising tool in the OHS field, and discusses related challenges (technical, ethical, biases and interpretation) and research perspectives.