<b><i>Background:</i></b> Kingdom of Saudi Arabia (KSA) is a country with one of the largest land masses and the most difficult geographical terrain in the Middle East. The accessibility of advanced health services, especially for people in rural areas, has been considered one of the main health challenges. To overcome this problem, many initiatives to embrace technology in healthcare were launched by the Ministry of Health (MOH). Despite the growth of utilizing eHealth interventions in the country, more research related to the end-users’ acceptance of eHealth services remains needed. This study aimed to investigate the relative importance of factors that influence health managers’ acceptance of eHealth services in KSA against behavioural intention (BI) and use behaviour (UB). <b><i>Methods:</i></b> An online questionnaire was designed based on two sources: first, the thirty-nine factors identified in a related systematic review to be relevant to eHealth acceptance in KSA, and second, the validated questionnaire adopted from the Unified Theory of Acceptance and Use of Technology (UTAUT) model. Participants were asked to rate the relative importance of the factors. The questionnaire was available in both Arabic and English. Professionals in KSA with a health management role from different backgrounds such as health professions, Health Information Technology, and administration were invited to take part. Participation links were distributed across social media platforms. Ethical approval had been gained. <b><i>Results:</i></b> 385 responses were received. Findings highlighted the relative importance of the main determinants that health managers in the KSA thought were important to influence their acceptance of eHealth services. The top rated influential factors were (i) availability of operational resources, (ii) privacy and security of health information, (iii) Information and Communication Technology infrastructure and readiness, (iv) availability of qualified human resources, and (v) quality of eHealth systems and applications. Of the UTAUT constructs, performance expectancy (PE) and social influence, which encapsulate factors such as management support, change resistance, and stakeholders’ voice that can play a crucial role in the acceptance of technology as part of daily work, showed significance to the BI, as well as facilitating conditions and PE to the UB. However, some results need further investigation to clarify ambiguity. <b><i>Conclusion:</i></b> Findings from this study may help address the current challenges and barriers and prioritize the main areas to improve eHealth acceptance in the KSA. Further research is planned to explore the identified factors across KSA through in-depth interviews.