Purpose – The present study investigates the factors that directly affect the use of Electronic Medical Records (EMRs) among healthcare professionals. Findings will contribute to our understanding of which explanation (deterministic vs. institutional) might be the most relevant to directly predict adopters’ behaviour, and whether institutional and rational factors are correlated, or represent two separate entities. Design/methodology/approach – Our model incorporates constructs from the Technology Accepts Model, i.e. perceived usefulness and ease of use, along with constructs associated with institutional explanations, i.e. organizational expectations, technological culture and alignment of meaning systems. We surveyed the literature to identify valid measures for related constructs and adapted existing scales to measure the different constructs. We developed a questionnaire and collected data from four public hospitals in Northern Italy that are early adopters of EMRs. We have run a hierarchical regression to test our hypotheses. Originality/value – The results provide full support to the TAM model, and only partial support to the hypothesis that institutional factors have a direct and indirect (i.e. mediated by TAM) effect on technology use. Results reveal, in fact, significant direct and mediated relationships only for organizational expectations. Practical implications – Comprehensively, our results provide healthcare managers with new insights on how to trigger and facilitate the adoption and the continuative usage of EMR within their operations. On the one hand, they have to understand how professionals evaluate the benefits and shortcomings of the innovations and provide them with clear, evidence-based information about EMRs. On the other hand, they cannot mandate change easily by means of top-down, hierarchical actions, but they can create the premises and the organizational facilitations that are conducive of change by professionals.