Objectives. This paper examines how statutory workweeks affect workers’ provision of long term care for their non-co-resident elderly parents. Methods. The Korean government reduced its statutory workweek from 44 to 40 hours, gradually from larger to smaller establishments between 2004 and 2011. We examine how the reduction affected visits, cash transfers, and in-kind transfers to parents using multiple regressions. Annual longitudinal data come from 2005 to 2013 waves of the Korea Labour and Income Panel Study. Results. The law change caused an increase in the frequency of visits and in-kind transfers among male workers with no significant impact on their cash transfers. Among female workers, we found impact on none of the outcomes. Discussion. We interpret the findings within the context of developed Asian countries with long work hours and Confucian tradition, and suggest regulating workweeks as a policy tool to encourage familial long term care in the rapidly aging societies.