INTRODUCTION AND HYPOTHESIS: Vaginal pessaries are the mainstay of the non-surgical management of pelvic organ prolapse (POP). A flexible silicone irregular hexagonal (SIH) pessary was developed based on the results of a prior vaginal case study. We hypothesised that the SIH pessary would have a higher rate of retention and self-management than the polyvinyl chloride (PVC) pessary. METHODS: This was a prospective non-blinded, randomised controlled trial with institutional review board approval. Eligible participants were randomised and fitted with the assigned pessary. They were reviewed 1 week, 6 months and 1 year after the initial pessary fitting. Participants who returned for follow-up completed the study questionnaires. The primary outcome was success, defined as continued use of the allocated pessary at 6 months. Secondary outcomes included the ability to perform pessary self-care, treatment satisfaction and pessary-related complications. Statistical tests were performed with alpha or statistical significance defined as a p value of ≤ 0.05, two-tailed. RESULTS: A total of 104 participants were randomised, with 52 subjects in each arm. Primary outcome data were analysed using per protocol analysis. Continuing pessary usage at 6 months was 68.1% for the PVC pessary group and 65.1% for the SIH group, with no statistically significant differences between the two groups (p = 0.765). Subjects with SIH were more likely to perform pessary self-care. There were no significant differences in subjects' satisfaction, quality-of-life scores or treatment complications between groups. CONCLUSIONS: The pessary continuation rate between the SIH and the PVC pessary groups was similar at 6 months. Participants with an SIH pessary were more likely to self-manage.