Access to health services is a concern around the world. Different strategies were developed, but Africa's rate remains the lowest. This article aims to contribute to the population's access to healthcare, and to assess the determinants of the use of mutual health insurance by the population of the Ziguinchor region in Senegal. Methods: The study is transversal and descriptive, carried out from July to August 2018. Through the quota method we defined the number of patients to be interviewed. Thus, by a geographic stratification according to the departments and a second-degree stratification taking into account the staff of the different hospital departments, 392 patients were selected. Results: 73% at the Regional Hospital Center and 27% at the Regional Peace Hospital. Response rate: 97%, women 60% and men 40%. The enrollment for women (24%) is slightly higher than that for men (21%). Socioeconomic factors. The rate of adherence is the highest of for patients with university level, followed by high school; income: the highest rate for patients with a monthly income between 200,000 and 500,000 FCFA, followed by patients with an income monthly between 100,000 and 200,000 FCFA. Factors linked to the provision of care: the rate of Mutual Health Insurance adherence follows distances from patients' homes. Concerning the relation to satisfaction, education, distance and information are more determining than adherence rate. Recommendations: 1) State: actions on education and distance; 2) Sensitizing the population on mutual health insurance; 3) Urging healthcare providers to reduce waiting times and respect schedules as well as appointments.