Background: Vaginitis is one of the most common complaints in women around the world. Cinnamon is one of the medicinal plants for which there is contradictory evidence of its effect on vaginitis. Objectives: This study aimed to evaluate the effect of cinnamon on the treatment and recurrence of candidal vaginitis. Methods: We performed this randomized, double-blind, placebo-controlled trial from April to August 2014 in Tehran, Iran. Totally 120 women aged 15 to 45 years clinically and paraclinical approved candidiasis vaginitis were included by convenient sampling at first and then were randomly allocated to 2 groups. The intervention group received 2.5 g of cinnamon powder. The control group received 2.5 g of placebo. Both groups should apply a vaginal applicator of clotrimazole cream (1%) daily. Vaginitis symptoms were evaluated with the researcher-made questionnaire and checklist at baseline, 4th, and 7th days of the treatment. Recurrence was evaluated 2 months later. Results: A significant decrease was seen in itching (from 83% to 11%) (P-value = 0.001), burning (from 71% to 5%) (P-value = 0.003), suprapelvic pain (from 65% to 3.3%) (P-value = 0.001), dyspareunia (from 80% to 7%) (P-value = 0.001) on the 7th day of the treatment in the cinnamon group. In the placebo group, a significant decrease was shown in itching (from 90% to 20%) (P-value = 0.001), burning (from 81.7% to 8.3%) (P-value = 0.001), dyspareunia (from 78% to 35%) (P-value = 0.001) and suprapubic pain (from 68% to 16.7%) (P-value = 0.001). After 2 months, recurrence was 45% in the cinnamon group (P-value = 0.001), but it was 71.7% in the placebo group (P-value = 0.003). No adverse effects of cinnamon were recorded. Conclusions: The efficacy of oral cinnamon capsule is better than clotrimazole vaginal cream in the treatment and recurrence of vaginal candidiasis. Therefore, the use of these products may be an effective remedy for vaginal candidiasis.