BACKGROUND: Therapeutic observance remains a major problem in managing diabetic subjects, just like in other pathologies treated by medication and lifestyle modification. This study aims to determine the rate of therapeutic observance among diabetic subjects in the province of Essaouira and to identify the factors that influence it.METHODS: A cross-sectional questionnaire survey was conducted among 498 type 1 and 2 diabetic subjects, regularly being checked at different health centers in the province of Essaouira (Morocco).RESULTS: Almost a quarter of the surveyed subjects (23.3%) had poor observance. The results of the binary logistic regression model show that, in order of importance, observance is associated with six factors: Availability and access to medical treatment (Odds Ratio OR: 3 ; 95% CI confidence interval [1.78-5.03]); the side effects related to the treatment (OR: 2.60 ; 95% CI [1.65-4.09]); the family support (OR: 1.58 ; 95% CI [0.95-2.61]); duration of diabetes (OR: 0.55 ; 95% CI [0.34-0.88]); the age (OR: 0.50 ; 95% CI [0.30-0.82]); awareness level about the disease (OR: 0.43 ; 95% CI [0.21-0.90])CONCLUSION: The results of the present study have allowed us to identify several factors that can influence therapeutic observance, that prove necessary to be considered and acted upon.KEYWORDS: Diabetes, medical treatment, observance, Morocco