This 6-year follow-up study investigates the impact of interpersonal conflict at work on work disability among 8,021 male and 7,327 female employees aged 24 to 65 years at baseline. Marital status, marital conflict, monotonous work, hectic work pace, hostility, neuroticism, life dissatisfaction, and experienced stress of daily activities were included in survival analyses, which were adjusted for age, social status, and general health status. Interpersonal conflict at work predicted work disability only among women (RR 1.56, CL 1.01-2.39). This risk was confined to women who reported simultaneous marital conflicts (RR 2.54, CL 1.03-6.22). When included in further analyses, life dissatisfaction was a significant risk factor among both genders, but monotonous work, neuroticism, and experienced stress of daily activities were risk factors only among men. These data suggest that interpersonal conflict could be a determinant of work disability, and this indicates the importance of gender and marital factors.