Background and purpose <p>Long-term care comes with risks, including caregiver strain. The strain negatively affects caregivers and care quality for the elderly. Enhancing resilience through education can lead to improved health outcomes. This research aimed to evaluate the effect of resilience education on family caregivers’ strain of older people with chronic diseases.</p> Methods <p>This randomized clinical trial was conducted in Amol, Iran from August 2022 to May 2023. Participants were 84 family caregivers of elderly people with chronic diseases. They were selected based on inclusion and exclusion criteria through continuous sampling and randomly allocated to an intervention and a control group using block randomization. Data collected by demographic and Robinson’s Caregiver Strain Index (13 items) questionnaire before, immediately after, and six weeks post-intervention. Resilience education consisted of six sessions delivered in person and electronically (via SMS) to the intervention group over three weeks, based on Henderson’s resilience components training program. Statistical analysis was performed using various tests in SPSS software (v. 16.0) at a significance level of less than 0.05.</p> Results <p>Analysis of variance with repeated measures by groups showed that caregiver strain in the control group did not have a statistically significant difference at any of the different times (<i>p</i> = 0.279). Two-by-two Bonferroni comparison showed that the caregiver strain immediately (18.11 ± 3.12) and six weeks after the intervention (18.78 ± 3.86) had a statistically significant difference compared to before the intervention (20.73 ± 3.51) (<i>p</i> &lt; 0.001).</p> Conclusion <p>The resilience education was found to be effective in significantly reducing family caregivers’ strain of older people with chronic diseases. Therefore, health centers managers and providers can use resilience education to alleviate strain among family caregivers.</p> Trial registration <p>The Thai Clinical Trials Registry TCTR20230424001 prospectively registered on 24 April 2023.</p>