This article aims to find the determinants that affect patient satisfaction regarding the Mawiidi public portal in Moroccan public hospitals and assess its outpatient online booking system effectiveness using a model that integrates the Technology Acceptance Model (TAM) with the Information Systems Success Model (ISSM) while adopting a quantitative research methodology. The analysis was conducted using 348 self-administered questionnaires to analyze eight key constructs, such as information quality, patient satisfaction, perceived ease of use, and privacy protection, among others. The results of PLS-SEM verified six out of eleven hypotheses tested, which reflected that information quality has a positive influence on perceived ease of use, which again enhances patient satisfaction. The major factors influencing the satisfaction and trust of patients in online appointment scheduling systems at public hospitals are highlighted. Indeed, privacy protection enhances patient satisfaction and trust. Service quality positively affects satisfaction but to a lesser degree. Website-related anxiety impacts perceived ease of use, although it has a limited influence on satisfaction. Such findings can inform suggestions for the managers of hospitals and portal designers to increase user satisfaction. This study uses a model from the TAM and ISSM frameworks, including cultural and socioeconomic aspects that apply to Morocco’s healthcare context.