Objectives: In France, one pregnancy out of three is unplanned. Half of those pregnancies lead to abortion. However, the use of emergency contraception is far from systematic. It is therefore relevant to question the reasons and factors linked to the low rate of use of emergency contraception., Methods: A retrospective observational study was conducted in the orthogenic service of the University hospital Center of Nice, over a six weeks period. Patients were consulting in the context of voluntary termination of pregnancy and were subjected to a questionnaire during a semi-structured interview. The collected data were: age, degree of education, profession, size of their home town municipality, legal status, obstetrical history, contraception used at the time of unplanned pregnancy, emergency contraception background and justification for not using an emergency contraception., Results: A total of one hundred and five questionnaires were studied. The absence of emergency contraception was due to an underestimation of the risk of pregnancy in 81% of cases. Among characteristic variables of the studied population, none was related to the non-use of emergency contraception., Conclusions: Independently of the patient profile, underestimation of the risk of pregnancy is the main cause of non-use of emergency contraception. It seems crucial to inform women with childbearing age and their families about their fertility and the basic mechanisms of fertility in order to reduce the number of unplanned pregnancies in France., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)