Antibiotic treatment is the most effective method for managing recurrent uncomplicated urinary tract infections (UTIs) in women. However, there is a limitation to long-term antibiotic use, therefore alternative approaches are required. Escherichia coli is the commonest cause of recurrent uncomplicated UTIs and accounts for more than 60% of recurrent cystitis. It has therefore been suggested that immunostimulation with a bacterial extract consisting of immunostimulating components derived from 18 E. coli strains may protect against UTIs. Many in vitro studies, animal experiments and clinical trials in patients with recurrent UTIs have been carried out to assess the effectiveness and safety of E. coli extract for prophylaxis against recurrent UTIs. In this paper, we review the scientific evidence showing the anti-inflammatory effect of E. coli extract as well as the clinical results of placebo-controlled, randomised, double-blind studies that demonstrated a positive effect for E. coli extract in patients with recurrent UTIs. Evidence from available studies suggests that E. coli extract can be beneficial and safe for preventing recurrent UTIs in women.