Background: Schizophrenia is a chronic, relapsing, mental disorder, and lack of adherence is a common and severe problem in such patients leading to global and heavy consequences for patients (relapses, hospitalizations, impaired quality of life…), for the family and for society. Improved understanding of the underlying reasons will help to form intervention strategies relevant to the context. Objectives: We aimed to assess medication adherence among stable patients suffering from schizophrenia and to identify factors associated with non-adherence. Methods: This is a retrospective cohort study of outpatients with schizophrenia at the psychiatric hospital Ar-razi of Salé (Maroc). The patients were aged over 18, clinically stabilized under the same treatment during the three months prior to inclusion. Data (demographic, clinical and therapeutic) was collected by a questionnaire developed for this purpose. Assessment of adherence and awareness of the disorder (insight) were performed respectively by two validated scales: Medication Adherence Rating Scale the (MARS) and scale Q8. Results: Forty percent of schizophrenic patients included in our study were not compliant to treatment. Compared to adherent patients, non-adherent patients had history of substance use (57.6 % vs. 42.4 %, P <0.05), were less aware of their disorder (77.8 % vs. 22.2 %, P <0.01), had significantly more drug intake per day (2.4 vs. 1.9, P <0.01), took significantly more tablets per day (2.8 vs. 2.2; P <0.05) and complained of significantly more side effects (43.2 vs. 56.8, P <0.05). A logistic regression model had shown that only side effects, lack of insight, and a history of substances use are significant predictors of poor adherence in patients with schizophreniConclusion: The results of this work should guide our efforts to improve adherence in patients with schizophreniWaiting for new drugs with fewer side effects and better benefit/risk, some strategies would help to improve adherence to treatment. For example: implementation of strategies to manage psychoactive substance use, structured psycho-educational strategies to improve insight, and training therapists to improve the therapeutic alliance should be established