Background Latina mothers who care for children with intellectual and developmental disabilities (IDD) over the lifespan struggle to take care of their own health needs in the context of their caregiving experience. Services are typically aimed at the persons with IDD and not their family caregivers. Yet, attending to family caregiver needs may contribute to better long‐term care of persons with IDD who remain at home. To address this unmet need, we developed a culturally sensitive health education intervention for Latina mothers who care for youth and adults with IDD. The aim of the intervention is to improve maternal health‐related self‐efficacy and health behaviours, and to reduce stress. Method A randomised control design was employed to determine preliminary efficacy of the intervention. Paired sample t‐tests were conducted to examine within‐group changes from baseline to 3‐month post‐test. Repeated‐measures analysis of covariance was used to examine the group‐by‐time interaction effects. Results Intervention participants showed greater increases between pre‐ and post‐test in health‐related self‐efficacy; self‐care, nutrition and overall health behaviours. Both groups reported decreases in depressive symptoms and caregiver burden. Conclusions While additional research is needed to determine long‐term effects and to replicate findings, our results suggest that this culturally sensitive health intervention is a promising way to increase health behaviours which may lead to overall good health for Latina mothers who care for children with IDD across the lifespan.