Purpose: To investigate the body weight, pulmonary function and quality of life of twenty patients with morbid obesity six months after the Fobi-Capella operation. Methods: Patients were evaluated before and six months after surgery. The patients were mainly female (75%), the average age was 40.5 ± 10.27 years; average weight 110.11 kg ± 21.77 and average body mass index (BMI) 39.93 ± 7.13 kg/m 2 in the postoperative evaluation. Pulmonary function was assessed by spirometry using a Pulmonet/Godart NV Bilt Vetr Hotland spirometer and quality of life was assessed by applying the Moorehead-Ardelt questionnaire. The pre-and postoperative spirometry values were compared by the paired Student t test and the correlation between weight loss and pulmonary function was determined by linear regression, with the level of significance set at p < 0.05. Results: The spirometry variables Respiratory Frequency (RF), Expiratory Reserve Volume (ERV) and Functional Residual Capacity (FRC) differed significantly between the pre-and postoperative periods, whereas Residual Volume (RV), Vital Capacity (VC), Total Lung Capacity (TLC), FEF (Forced Expiratory Flow between 25 and 75% FVC) and FEV1/FVC% (Forced Expiratory Volume in the 1 st second/ Forced Vital Capacity ratio) did not differ between periods. Only one patient reported worsening of quality of life. There was a positive correlation between weight loss and ERV (p=0.0117, r=0.5514), but no correlations were observed for the other variables. Conclusions: There was a significant weight loss and an improvement of pulmonary function as seen by respiratory frequency, reduction and increased expiratory reserve volume and functional residual capacity. The quality of life of the patients also improved after the Fobi-Capella operation. Key words: Obesity, Morbid. Respiratory Function Tests. Quality of Life. Bariatric Surgery. RESUMOObjetivo: Investigar a evolução do peso corpóreo, da função pulmonar e da qualidade de vida de 20 pacientes obesos mórbidos seis meses após operação de Fobi-Capella. Métodos: Os pacientes foram avaliados antes e seis meses após a cirurgia e o sexo feminino predominou em 75%, com média de idade de 40,5 anos ± 10, 27, média de peso de 110,11 kg ± 21,77 e IMC de 39,93 kg/m 2 ± 7,13. Para a avaliação da função pulmonar foi realizada espirometria por meio do espirômetro Pulmonet Godart NV Bilt Vetr Holland, e para a qualidade de vida foi aplicado o questionário de Moorehead-Ardelt. As comparações entre os valores espirométricos do pré e do pós-operatório foram realizadas pelo teste t de Student para amostras pareadas, e para a correlação entre a perda de peso e função pulmonar utilizou-se análise de regressão linear simples, adotando-se p < 0,05 para todos os resultados. Resultados: As variáveis espirométricas Freqüência Respiratória (FR), Volume de Reserva Expiratório (VRE) e Capacidade Residual Funcional (CRF) apresentaram, aos seis meses após a operação, diferença estatisticamente significativa com os valores pré-operatórios, porém, não houve diferença ...