The concept of gendered work organization points to how work assignments and employment conditions are segmented on the basis of gender. Case evidence from three Japanese customer-service workplaces demonstrates how the segmentation of women's work from men's job roles, in part a result of the two-track employment system, effectively blocks career opportunities for women. Gender relations on the office floor reproduce the subordinate position of female workers in daily working life, but female workers are not entirely acquiescent. The three case studies point to important differences in the gendering of work organization and workplace culture. One case, a foreign-owned multinational financial services company, was in the midst of a de-segmentation and re-evaluation of customer-service work, with the consequence that men were being integrated into the workplace, and women's work assignments and employment conditions included career opportunities. Two Japanese-owned companies displayed the opposite trend. The increasing importance of customer-service and sales work in these cases was coupled with a strategy of rationalizing the work assignments of women, and personnel practices favored core male employees. The responses of women workers are interpreted in the context of differences in gendered work organization and employment conditions.