Background Various determinants of nurses' work motivation and turnover behavior have been examined in previous studies. In this research, we extend this work by investigating the impact of care setting (nursing homes vs. home care services) and the important role of rest break organization. Objectives We aimed to identify direct and indirect linkages between geriatric care setting, rest break organization, and registered nurses' turnover assessed over a period of one year. Design We designed a multimethod cross-sectional study. Setting 80 nursing units (n = 45 nursing homes, n = 35 home care) in 51 German geriatric care services employing 597 registered nurses. Methods We gathered documentary, interview, and observational data about the organization of rest breaks, registered nurses' turnover, and additional organizational characteristics (type of ownership, location, nursing staff, clients, and client-to-staff-ratio). Results The findings show that the rest break system in geriatric nursing home units is more regularly as well as collectively organized and causes less unauthorized rest breaks than in home care units. Moreover, the feasibility of collective rest breaks was, as predicted, negatively associated with registered nurses' turnover and affected indirectly the relation between care setting and registered nurses' turnover. Care setting, however, had no direct impact on turnover. Furthermore, registered nurses' turnover was higher in for-profit care units than in public or non-profit units. Conclusions This study reveals significant differences in rest break organization as a function of geriatric care setting and highlights the role of collective rest breaks for nursing staff retention. Our study underlines the integration of organizational context variables and features of rest break organization for the analysis of nursing turnover.