Resumo: Introdução: A obesidade tem sido associada a eventos respiratórios e a maioria destes ocorrem no pós-operatório imediato na unidade pós-anestésica (UPA). O objetivo deste estudo foi avaliar o «outcome» e a incidência de eventos adversos respiratórios (ARE) pós-operatórios em doentes com obesidade durante a sua permanência na UPA. Métodos: Estudo prospetivo caso-controlo com emparelhamento de 27 pares de adultos com obesidade e doentes com IMC  0,025). A análise multivariada identificou a obesidade e o bloqueio neuromuscular residual como fatores de risco independentes para a ocorrência de eventos respiratórios. A duração da estadia na UPA foi superior nos doentes obesos (120 min vs 84 min, p > 0,01). Conclusões: A incapacidade de respirar profundamente foi o ARE mais frequente no período pós-operatório imediato nos doentes obesos. A obesidade foi considerada um fator de risco independente para ocorrência de ARE na UPA. Os doentes obesos tiveram maior tempo de estadia na UPA mas não tiveram maior tempo de internamento hospitalar. Abstract: Introduction: Obesity has been associated with respiratory complications, and the majority of these complications occur in the Post-Anesthesia Care Unit (PACU). The aim of this study was to evaluate the outcome and incidence of adverse respiratory events (AREs) in obese patients during their stay in the PACU Methods: We conducted a prospective control study that included 27 obese patients matched with an equal number of patients with body mass index (BMI) < 30 (non-obese control group); the 2 groups of patients were similar in respect to gender distribution, age, and type of surgery and had been admitted into the PACU after elective surgery (May 2011). The AREs were identified during PACU stay. Descriptive analysis of variables was performed, and the Mann-Whitney U test, Chi-square test, or Fisher's exact test were used for comparisons. Associations with AREs were studied using univariate and multivariate logistic regression models. Results: There was a higher frequency of STOP-BANG â¥Â 3 (89% vs. 11%, P < .001) among obese patients and they were less frequently scheduled to undergo high-risk surgery (7% vs. 41%, P = .005) and major surgery (4% vs. 15%, P = .008). Obese patients had more frequent AREs in the PACU (33% vs. 7%, P < .018). Multivariate analysis identified obesity and residual neuromuscular blockade as independent risk factors for the occurrence of AREs. Stay in the PACU was longer for obese patients (120 min vs. 84 min, P < .01). Conclusions: Obesity was considered an independent risk factor for AREs in the PACU. Obese patients stayed longer in the PACU, but they did not stay longer in the hospital. Palavras-chave: Obesidade, Ãndice de massa corporal, Eventos respiratórios, Resultados pós-operatórios, Keywords: Obesity, Body mass index, Respiratory events, Postoperative outcome