Objective The aim of this study was to investigate the impact of intensive grandchild care on depressive symptoms among grandparents. Methods We used data from 2008 to 2012 of the Korea Longitudinal Study of Aging. Using the data from 2008 at baseline, data included 5129 individuals aged 50 years and more without depression with at least one grandchild. A generalized estimating equation was used to investigate the impact of intensive grandchild care on depressive symptoms. Investigated factors included the intensity of grandchild care, measured by hours spent caring for a grandchild per week: (i) none (0 h); (ii) non‐intensive grandchild care (1–39 h); and intensive grandchild care (≥40 h). Depressive symptoms were measured using the 10‐item Center for Epidemiological Studies Depression scale. Results Among 5128 participants from 2008 to 2012, 3.0% were providing non‐intensive grandchildren care, and 1.9% were providing intensive grandchild care. Compared with grandparents providing no grandchild care, those who provided intensive grandchild care experienced reduced depressive symptoms (β = −0.51 [p = 0.007] vs. no childcare). Men (β = −1.22 [p = 0.012] vs. no childcare) providing intensive grandchild care experienced a greater reduction in depressive symptoms compared with women (β = −0.44 [p = 0.029] vs. no childcare) providing grandchild care. Grandparents who were receiving financial support from adult children were more likely to experience reduced depressive symptoms than those not receiving such support. Conclusion The results of this study reveal that intensive grandchild care is associated with lower depressive symptoms among older adults, particularly men. The findings emphasize the importance of encouraging older adults to participate in grandchild care, regardless of gender. Copyright © 2016 John Wiley & Sons, Ltd.