This paper describes the synthesis of field research comprising a cross-case analysis of the digital health ecosystems of Singapore and the United States. The two cases were selected using the ‘purposive sampling’ approach based on the sampling strategies of ‘maximum variation’ and ‘information richness’. The insights extracted are used to derive some critical success factors for a sustainable e-health ecosystem. The new knowledge acquired through the cross-case analysis is compared with the literature for theoretical integration. The paper concludes with a brief account of some key findings.