OBJECTIVES As pain is a subjective and difficult parameter to assess in children, we aimed to evaluate the correspondence of two pain scales - parents' post-operative pain measure (PPPM) and faces pain scale-revised (FPS-R) with analgesic intake in the assessment of post-tonsillectomy pain in a pediatric population. METHODS Children aged 4-10 years (n=174) undergoing tonsillectomy with or without adenoidectomy had their pain monitored by PPPM and FPS-R over 7 days following surgery. The amount of analgesic (acetaminophen or dipyrone) intake was also recorded each day. Linear regression and correlation analysis were performed for pain scales and Poisson regression model for analgesic administration. To evaluate influence of gender linear regression and logistic regression with random effects were performed. RESULTS PPPM and FPS-R presented a significant positive correlation (τ=0.5; R(2)=0.36; p<0.001). PPPM and FPS-R also showed a significant correlation with analgesic use over the 7 post-operative days (p<0.0001). No influence of gender was observed in pain levels by both scales. CONCLUSIONS Our data demonstrate that PPPM and FPS-R are equivalent pain scales to quantify post-tonsillectomy pain in children and are useful tools in post-tonsillectomy clinical research.