Morbid obesity is a disease affecting the health of thousands of people around the world, representing a great economic burden for health services. One of the most effective methods of weight reduction is bariatric surgery; however this procedure is commonly used only after other weight reduction methods have failed. This study explores the importance of certain elements as pre- and post-surgery motivators, as well as their relevance in the evolution of the bariatric patient. In this qualitative study we analyzed the discourse of 9 morbid obese people who had gone through bariatric surgery to lose weight, to identify their motivation to do the bariatric procedure, as well as doing and keeping changes to their lifestyle after surgery. We found that the most important motivating factors in pre-surgery period are fear of suffering diseases derived from their morbid obesity, and failure of other weight reduction methods; in postsurgery period, the main motivators to do and keep lifestyle changes are family support and desire to be able to do physical activities. We conclude that motivation should be considered in the treatment of bariatric patients, and treated by a psychologist as part of a multidisciplinary team of health experts.