Abstract: The popularity of elective cosmetic surgery has risen rapidly over the last two decades, drawing attention to its pursuit and psychological effects. However, the literature shows mixed results regarding the psychological outcomes of cosmetic surgery, suggesting methodological weaknesses across a majority of the studies, and lending weight to the belief that there is insufficient evidence to demonstrate the psychological benefits of cosmetic surgery. The current study explores the psychological change in cosmetic surgery patients before and six months after the surgery, using mixed methods of applied longitudinal analysis and thematic analysis. It explores the psychological differences between 17 prospective cosmetic surgery patients and a comparison group of 20 not planning cosmetic surgery, examines why patients undergo surgery, and looks at factors that could influence surgery outcomes. Psychological measures were taken before the surgery and two weeks, three months and six months after the surgery. The psychological outcome variables include global self-esteem, appearance evaluation and orientation, psychological wellbeing and body image-related quality of life. No psychological difference was found between prospective cosmetic surgery participants and the comparison group, except that the surgery participants were more dissatisfied with their overall appearance and their body image experiences were more likely to have negatively affected their lives preoperatively compared with the comparison group. Cosmetic surgery was sought to address concerns and dissatisfaction over physical appearance, and under the expectation of postoperative psychological enhancement. Cosmetic surgery participation was significantly associated with increased appearance satisfaction over time, whereas no significant changes was found in other psychological variables. The majority of the postoperative cosmetic participants reported that their appearance dissatisfaction in other parts of their bodies have a somewhat negative impact on their lives, whereas the comparison group described that such appearance dissatisfaction has no effect on their lives or minor preoccupation at the most. Implications for future research and clinical practice are discussed.