ObjectiveThe incidence of recurrent peritonsillar abscess (7.4–22%) was estimated in retrospective studies. The aim of this prospective study was to estimate the cumulative incidence of recurrent peritonsillar abscess and related risk factors. MethodsWe performed a prospective longitudinal cohort study. The study included adult patients (≥18 years old) of both sexes who were attended in the emergency facilities of our tertiary hospital, without peritonsillar abscess background, diagnosed of a first episode of peritonsillar abscess and treated with standard of care (abscess drainage and antibiotics). Patients were followed for 24 months. Cumulative incidence of peritonsillar abscess recurrence was estimated and its 95% confidence interval was calculated; and predictive risk factors were assessed. ResultsBetween January 1st, 2019 and March 9th, 2020, a total of 181 consecutive patients were included. The cumulative incidence of recurrent peritonsillar abscess at 2 years of the diagnosis was 9.9% (18 out of 181, 95% CI: 6.4–15.2%). The only risk factor associated with recurrent peritonsillar abscess in multivariate analysis was low plasma glucose level at the time of emergency room attendance (HR: 0.46, 95% CI: 0.24–0.91, p-value: 0.026). ConclusionPeritonsillar abscess is an incident medical issue, with an established recurrence rate, but with unclear predictive risk factors of recurrence. Further studies are needed to assess the risk factor associated with recurrent peritonsillar abscess.