International migrant men in Nepal usually leave behind their wives and children resulting in a transnational relationship often lasting years. Considering the universality of marriage in Nepal, Nepal’s patriarchal culture which places women below their husbands and in-laws and high rates of men’s international labour migration, it is imperative to understand how prolonged separation affects the wives who remain behind. This study explores the impact of international labour migration on the marital relationship and health of wives who remain behind in Nepal. A mixed-method study was conducted in Pahli Nandan Rural Municipality of Nawalparasi West district and Aanbu Khaireni Rural Municipality of Tanahun district of Nepal. A cross-sectional survey was conducted with 200 migrant wives and 201 co-habiting wives. Hierarchical linear regressions were conducted to determine associations between the variables of interest. Four key informant interviews with municipality staff and female community health volunteers, and 15 in-depth interviews with migrant wives were conducted. Thematic analysis was used to analyse qualitative data. Survey and interview data were integrated using joint-display tables. Mixed-method findings showed better marital quality among migrant wives than co-habiting wives. The reasons for this appeared to be the remittance the migrant wives received from husbands and regular communication over internet applications. Mixed-method findings showed no significant impact of husbands’ migration on the physical and mental health of migrant wives. Findings showed that remittances led to increased affordability of health services and increased financial security. However, the increased workload in their husbands’ absence, including managing remittances, affected their health negatively. Therefore, both positive and negative health impacts of husbands’ migration were noted with a net insignificant impact on health. Mixed-method findings showed that marital quality did not have a significant impact on the health of migrant wives. Longitudinal or pre- and post-migration designs are required to better understand the impact of men’s migration on the marital relationship and health of wives prior to and after husbands’ migration. Policy recommendations include establishing a support mechanism in the form of individual or group counselling/awareness programmes for migrant wives comprising information on the importance of spousal communication, health risks, financial management skills and managing workload.