Objectives Global ageing is linked to an increased burden of cardiovascular disease and dementia, which calls for better prevention strategies. Self-management and eHealth applications are regarded as promising strategies to support prevention. The aim of this study was to explore nurses’ best practices concerning behaviour change guidance for cardiovascular (CV) prevention in order to learn how to optimally integrate them into a coach-supported internet platform for CV self-management. Design Qualitative focus group study in Finland and the Netherlands. Discussions were audiotaped and transcribed. Data were thematically analysed following principles of grounded theory. Setting Dutch and Finnish primary care settings. Participants Six Finnish and seven Dutch primary care nurses with experience in CV prevention. Results Similar best practices were found in both countries and comprised of (1) establishing a relationship of trust, (2) managing awareness and expectations and (3) appropriate timing and monitoring of the process of behaviour change. However, the Finnish and Dutch nurses used different approaches for accomplishment of these practices, which was reflected in their recommendations for online support. Both groups emphasised that online support should be combined with human support and integrated into regular care. Finnish nurses had more confidence in patient self-management and remote communication than Dutch nurses, who emphasised the importance of face-to-face contact and preferred to keep control of medical aspects of prevention. Conclusions Differences in Dutch and Finnish’s nurses’ practices for supporting CV prevention appear to reflect their local healthcare practices, which should be taken into account when designing internet platforms for health self-management. Including cognitive health as a goal of CV prevention might stimulate motivation for health behaviour change. Trial registration number ISRCTN48151589 ; Pre-results.