Care services pose new challenges and opportunities for the implementation of sustainable HRM practices related to worker involvement and well-being because of their relational nature. The article is framed in terms of the job demands and resources model and discusses the impact of sustainable HRM (SHRM) practices on organizational performance in terms of service quality and organizational innovation in social and care services. A possible mediating role of immaterial satisfaction between SHRM and performance is also considered. We use national survey data including 4134 workers in 310 matched nonprofit social enterprises in Italy. The results show that HRM practices linked to task autonomy, teamwork, and involvement positively influence immaterial satisfaction, while at the same time immaterial satisfaction and HRM features related to involvement and workload support performance. The mediating role of immaterial satisfaction is not confirmed, but its effect adds positively to involvement in improving performance. This work contributes to the literature on organizational performance and HRM sustainability, which are particularly important in the face of ongoing social change and organizational innovation in social and relational service delivery.