Aim The public mandatory long‐term care insurance system in Japan has supposedly mitigated the care burden for family caregivers of older adults, whereas family caregivers still play a considerable role in providing care. The effect of informal caregiving on the caregiver's health has been of great interest. We investigated the relationship between the amplitude of informal caregiving and caregiver participation in health check‐ups in Japan. Methods The present study was a cross‐sectional analysis of nationally representative data in Japan (2010 Comprehensive Survey of Living Conditions). We investigated the relationship between care recipients’ care‐need level and in‐home caregiver participation in health check‐ups during the last year of the survey for caregivers. Results A total of 3354 caregiver/recipient pairs were included in the study. Crude proportions of caregivers completing a health check‐up by care‐need level were 68.4% (support required 1 and 2), 63.5% (care required 1–3) and 60.3% (care required 4 and 5). Higher care‐need level was negatively associated with caregiver participation in health check‐ups (support required 1 and 2as reference, care required 1–3: odds ratio 0.82, 95% confidence interval 0.75–0.90), care required 4 and 5: odds ratio 0.76, 95% confidence interval 0.74–0.79) after adjustment for possible confounders. Inclusion of the caregiver time devoted to care per day and caregiver self‐rating of health as independent variables did not change the result. Conclusions These results suggest that facilitating health check‐up participation for family caregivers of care recipients with higher care‐need levels might be an effective intervention for decreasing the gap in health behavior possibly caused by informal caregiving. Geriatr Gerontol Int 2017; ••: ••–••.