Background  An obesity epidemic is spreading worldwide. In addition to comorbidities, social and emotional problems contribute to reduce the quality of life (QoL) of obese people. Considering the heterogeneity of outcomes from clinical and surgical approaches, it is recommended that severely obese patients participate in their treatment decisions. This study evaluated preferences of severely obese patients for obesity surgical treatment using the willingness to pay (WTP) and to assess the impact of the presence of some clinical disorders, socioeconomic conditions and QoL on their decisions.Methods  The selected patients were invited to answer the WTP questionnaire using two formats of contingent valuation questions: dichotomous choice (yes/no) and a bidding game. The answers were correlated with clinical features, QoL assessed by the SF‐36 and the Moorehead‐Ardelt Quality of Life Questionnaire II, Brazilian socioeconomic classification, and family and personal incomes.Results  The group of patients who accepted the first bid was older and had higher frequency of sleep apnoea when compared to those who rejected the offer. A significant correlation between the bidding game value and family income was found (r = 0.28; P < 0.02). In the logistic regression model, socioeconomic classification and sleep apnoea were shown to be independently associated with acceptance the bid.Conclusions  Sleep apnoea was the comorbidity that most influenced the acceptance in dichotomous choice for bariatric surgery, probably due to the deleterious effects on daily activities induced by sleep disturbances. Our findings also suggest that the frequency of surgical procedures is below the preference of the obese population in Brazil.