INTRODUCTION: Vaginal pessaries are offered as a first-line treatment for symptoms associated with pelvic organ prolapse (POP). The objective of our study was to identify risk factors for failure of pessary use within 1 year of insertion. MATERIALS AND METHODS: We prospectively included women who accepted a pessary fitting for symptomatic POP. Symptoms and quality of life were assessed at inclusion, 1 month, 6 months, and 1 year after insertion using validated questionnaires (PFDI-20, ICIQ-SF, PISQ-12, USP and PFIQ-7). Patient satisfaction was assessed by the PGII score. Pessary failure was defined as stopping pessary use during the period. RESULTS: Of the 206 women included, 175 had available results at 1 year. Of these, 70 (40.0 %) had pessary failure and 105 (60.0 %) were still wearing the pessary. The overall PFDI-20 symptom score and its subscores were significantly improved as early as 1 month after pessary insertion. Factors associated with pessary failure at 1 year were: a younger age at insertion (RR CONCLUSION: The vaginal pessary is an effective treatment for women with symptomatic POP and improves their quality of life. Risk factors for pessary failure are diverse but clinical characteristics such as a large GH or short TVL seem to be associated with pessary failure due to higher expulsion rates. Satisfaction at 1 year is high among pessary users.