Bariatric surgery is the most effective treatment for weight loss in individuals with severe and complex obesity. While the extant literature has mostly explored clinical outcomes of surgery, recent research has also examined patients' experiences prior to treatment. This systematic review synthesized findings from qualitative studies investigating patients' motives and expectations prior to undergoing bariatric surgery for weight loss. Twenty-eight studies published in English involving 580 participants were identified for inclusion. Data extraction and thematic synthesis yielded four global themes: physiological, emotional, cognitive, and interpersonal/environmental. These represented seven subthemes describing patients' presurgery experiences: relationship with food, physical health, activities of living, personal identity, social relations, presurgery information, and beliefs about surgery. In addition to improving physical and medical comorbidities associated with obesity, participants believed that postsurgery weight loss would produce positive psychosocial impacts by strengthening their personal identities, their relationships, and improving their engagement in public and professional life. The complex and widespread nature of the changes patients expected would result from bariatric surgery highlights the importance of providing pretreatment education focused on psychosocial well-being, as well as concurrent psychological support alongside surgery, to best inform individual treatment selection and clinical practice.