A growing literature indicates that organizational and work demands place pressure on the partners and families of volunteer workers as it does on paid workers. This study evaluated a conceptual model integrating work-family conflict and stress crossover theoretical frameworks, to investigate the mechanisms by which emergency service volunteer work, specifically, predicts outcomes for the partners of volunteers. Matched data from 102 couples in which one partner was an Australian emergency services volunteer - firefighter, ambulance officer or emergency rescue volunteer - were analysed using structural equation modelling analyses. Findings suggested that one mechanism by which inter-role conflict related to partner adjustment was through elevated withdrawn marital behaviour and decreased intimacy reported by the couple, which indirectly affected partners' distress. This finding regarding withdrawn behaviour appears to be novel and may also be applicable to paid workers. Alternative mechanisms involving role overload and angry marital behaviour were not supported. These findings extend limited research which has adapted organizational theory to understand processes affecting volunteer workers, and advance conceptual accounts of the mechanisms through which the partners and families of workers are impacted by inter-role conflict.