This article provides a guide to conducting a data protection impact assessment (DPIA) for data sharing within health science research. Given the sensitivity of data in health sciences, a DPIA is vital to ensure adherence to data protection regulations and safeguard individual rights and privacy. This guide outlines the core components of a DPIA, including defining its purpose and scope, evaluating the necessity of data processing activities, gauging potential risks, and strategizing effective risk mitigation. By demystifying the DPIA process, this article empowers researchers and stakeholders to execute responsible and ethical data practices in line with the General Data Protection Regulation (GDPR) standards. Additionally, it offers practical examples, tools and resources to enhance the efficiency of conducting DPIAs in health science projects.