BACKGROUND:Countries vary in the extent to which reforms have been implemented expanding nurses' Scopes-of-Practice (SoP). There is limited cross-country research if and how reforms affect clinical practice, particularly in hospitals. This study analyses health professionals' perceptions of role change and of task shifting between the medical and nursing professions in nine European countries. METHODS:Cross-sectional design with surveys completed by 1716 health professionals treating patients with breast cancer (BC) and acute myocardial infarction (AMI) in 161 hospitals across nine countries. Descriptive and bivariate analysis on self-reported staff role changes and levels of independence (with/without physician oversight) by two country groups, with major SoP reforms implemented between 2010 and 2015 (Netherlands, England, Scotland) and without (Czech Republic, Germany, Italy, Norway, Poland, Turkey). Participation in 'medical tasks' was identified using two methods, a data-driven and a conceptual approach. Individual task-related analyses were performed for the medical and nursing professions, and Advanced Practice Nurses/Specialist Nurses (APN/SN). RESULTS:Health professionals from the Netherlands, England and Scotland more frequently reported changes to staff roles over this time period vs. the other six countries (BC 74.0% vs. 38.7%, p < .001; AMI 61.7% vs. 37.3%, p < .001), and higher independence in new roles (BC 58.6% vs. 24.0%, p < .001; AMI 48.9% vs. 29.2%, p < .001). A higher proportion of nurses and APN/SN from these three countries reported to undertake tasks related to BC diagnosis, therapy, prescribing of medicines and information to patients compared to the six countries. Similar cross-country differences existed for AMI on prescribing medications and follow-up care. Tasks related to diagnosis and therapy, however, remained largely within the medical profession's domain. Most tasks were reported to be performed by both professions rather than carried out by one profession only. CONCLUSIONS:Higher levels of changes to staff roles and task shifting were reported in the Netherlands, England and Scotland, suggesting that professional boundaries have shifted, for instance on chemotherapy or prescribing medicines. For most tasks, however, a partial instead of full task shifting is practice.