Uncontrolled postoperative pain and prolonged immobilization after bariatric surgery have been associated with increased postoperative complications and prolonged hospitalization. The aim of our study was to evaluate the postoperative pain that follows bariatric surgery and identify any psychological factors that may affect the early postoperative perception of pain. The study included 100 patients with obesity (women, n = 61; age 37.4 ± 9.9 years, mean ± standard deviation; Body Mass Index (BMI) 47.6 ± 6.5 kg/m2) who underwent bariatric surgery. Preoperative anxiety and depression were evaluated by the Hospital Anxiety and Depression Scale (HADS), and the quantitative and qualitative dimension of early postoperative pain were evaluated by the McGill Pain Questionnaire Short Form (MPQ-SF). Furthermore, the postoperative analgesia protocol was recorded for each patient. Pain declined gradually during the first 24 h postoperative. Although preoperative anxiety had no correlation with the overall pain of postoperative Day 0, patients with a higher level of preoperative anxiety had significantly more intense and more unpleasant pain at 1 h post operation. In addition, depression influences both the intensity and unpleasantness of pain at different time points (1 h, 4 h and 24 h postoperative). Preoperative pain correlated with educational level, but not with age, BMI, gender, marital status, smoking and surgery type. In conclusion, preoperative anxiety and depression influence the early postoperative pain after bariatric surgery, and their preoperative identification is of major importance to enhance the implementation of fast-track postoperative protocols to prevent complications and prolonged hospitalization.