Background: The aim of the present study was to evaluate the clinical effects of one‐stage periodontal debridement with an ultrasonic instrument, associated with 0.5% povidone (pvp)‐iodine irrigation in patients with chronic periodontitis.Methods: Forty‐five patients were randomly assigned into three groups: the control group (CG) received quadrant root planing at 1‐week intervals over four consecutive sessions; the periodontal debridement plus pvp‐iodine group (PD‐PIG) received a 45‐minute full‐mouth debridement with an ultrasonic instrument, associated with 0.5% pvp‐iodine irrigation; and the periodontal debridement group (PDG) received a 45‐minute full‐mouth periodontal debridement with an ultrasonic instrument, associated with NaCl irrigation.Results: At the 3‐month evaluation, the mean probing depth (PD) reduction in CG was 2.51 ± 0.52 mm, 2.53 ± 0.50 mm in PD‐PIG, and 2.58 ± 0.60 mm in PDG (P <0.05). The clinical attachment level (CAL) analysis showed a statistically significant gain in all groups compared to baseline (1.87 ± 0.56 mm [CG], 1.94 ± 0.70 mm [PD‐PIG], and 1.99 ± 0.92 mm [PDG]). Intergroup analysis of PD and CAL at 1 and 3 months showed no differences (P >0.05). The N‐benzoyl‐L‐arginine‐p‐nitroanilide (BAPNA) test showed a significant reduction in trypsin activity only during the first month (P <0.05); at 3 months there were no differences compared to baseline (P = 0.80).Conclusion: This study provides no evidence that pvp‐iodine is effective as an adjunct for one‐stage periodontal debridement.