Using a unique database of 204 employees in Senegal, this paper seeks to understand the determinants leading to the choice to enroll (or not) in a health insurance plan. To answer this question, we created three surveys to test certain preferences (time preference and risk aversion) and the role of information. In this paper, we show that Senegalese employees have a very strong preference for the present and a low aversion to loss, which could cause them to not take out insurance. We find that access to information on health insurance plays an essential role in the willingness to enroll . While 12% of employees who received no information about health insurance said they would not want to be insured if they could choose, this proportion dropped to 2% among employees who received positive information about health insurance. These results are econometrically confirmed when controlling for other factors such as gender, age and education. These results show the importance of information on people's perception of health insurance. It is therefore essential to communicate on the functioning of health insurance and the benefits of being covered in order to strengthen adherence to a health insurance system.