Environmental responsibility has been a widespread and relatively recent research theme in the healthcare sector. Considering that the greater life expectancy increases the need for healthcare services and that these services produce negative environmental externalities on human health, it is important to understand the relationship between environmental responsibility and the healthcare sector. This article aims to investigate what motivates hospital managers to adopt environmental responsibility programs and to identify the actions implemented by them. A multiple case study was conducted involving four Brazilian hospitals based in Rio de Janeiro and São Paulo. The results indicate that the main drivers are competitive, ethical and regulatory and that the competitive and regulatory motivators have the potential to establish a baseline for environmental performance that varies across ownership type (public or private). The results also indicate that the comprehensiveness of environmental actions is related to organizational resilience and to the motivators that drive hospitals to adopt those actions. Two conceptual models are proposed to illustrate these findings and offer bases for further research.