BACKGROUND: A community-based health insurance scheme operated by the Self-Employed Women's Association in Gujarat, India reported that the leading reasons for inpatient hospitalisation claims by its members were diarrhoea, fever and hysterectomy - the latter at the average age of 37. This claims pattern raised concern regarding potentially unnecessary hospitalisation amongst low-income women. METHODS: A cluster randomised trial and mixed methods process evaluation were designed to evaluate whether and how a community health worker-led education intervention amongst insured and uninsured adult women could reduce insurance claims, as well as hospitalisation and morbidity, related to diarrhoea, fever and hysterectomy. The 18-month intervention consisted of health workers providing preventive care information to women in a group setting in 14 randomly selected clusters, while health workers continued with regular activities in 14 comparison clusters. Claims data were collected from an administrative database, and four household surveys were conducted amongst a cohort of 1934 randomly selected adult women. RESULTS: 30% of insured women and 18% of uninsured women reported attending sessions. There was no evidence of an intervention effect on the primary outcome, insurance claims (risk ratio (RR) = 1.03; 95% confidence interval (CI) 0.81, 1.30) or secondary outcomes amongst insured and uninsured women, hospitalisation (RR = 1.05; 95% CI 0.58, 1.90) and morbidity (RR = 1.09; 95% CI 0.87, 1.38) related to the three conditions. The process evaluation suggested that participants retained knowledge from the sessions, but barriers to behaviour change were not overcome. CONCLUSIONS: We detected no evidence of an effect of this health worker-led intervention to decrease claims, hospitalisation and morbidity related to diarrhoea, fever and hysterectomy. Strategies that capitalise on health workers' role in the community and knowledge, as well as those that address the social determinants of diarrhoea, fever and the frequency of hysterectomy - such as water and sanitation infrastructure and access to primary gynaecological care - emerged as areas to strengthen future interventions.