Introduction: Non-adherence to treatment is a major issue in the management of schizophrenia. Objectives: To evaluate medication adherence among patients with schizophrenia and to identify predictive factors of poor therapeutic adherence. Methods: This is a cross-sectional study conducted among patients with schizophrenia at Ar-Razi Hospital in Salé, Morocco, from January 1 to March 31, 2024. Data collection (sociodemographic, clinical, and therapeutic) was carried out using a specifically designed questionnaire. Medication adherence was assessed using the Medication Adherence Rating Scale (MARS), and insight was evaluated using the Q8 scale. Results: In our study, 44.4% of the included schizophrenia patients were non-adherent. Poor therapeutic adherence was associated with lower socioeconomic status, lack of employment, lack of family support, substance use, negative insight, and a higher number of medication doses. Conclusion: The implementation of therapeutic and preventive strategies to address substance use, structured psychoeducational strategies to improve insight, and training for therapists to enhance the therapeutic alliance should be established to improve medication adherence among patients with schizophrenia.