Background. The purpose of our study is to compare the results of supine and lateral decubitus positions for total hip arthroplasty (THA) with the direct lateral (DL) approach in overweight and obese patients. Methods. Patients who had a THA with the DL approach using the lateral decubitus position (LD group) (n=54) or supine position (S group) (n=45) were retrospectively investigated. Demographic characteristics, age, and body mass indexes were calculated. Blood loss of patients, amount of transfusion, Harris Hip Scores (HHSs) (preop, 6 weeks, 3 months, 6 months, and 12 months), incision size, surgery time, postoperative acetabular cup inclination angle, femoral stem alignment, follow-up period, hospital stay, preoperative-postoperative leg length inequality, and complication rates (infection, wound site problems, and dislocation rates) were compared. Results. Both groups did not differ from each other by means of age, gender, BMI, and affected side (p=0.814, p=0.723, p=0.582, and p=0.833, respectively). The incision length (p<0.001), blood loss (p=0.010), and amount of blood transfused (p=0.002) were significantly higher in the S group than in the LD group. The surgical time was significantly longer in the S group (p<0.001). There were no statistically significant differences between the LD and S groups in terms of pre- and postoperative height, cup inclination, stem alignment, duration of hospital stay, and follow-up period. The change between pre- and postoperative HHS in the LD and S groups was statistically significant. Post hoc binary comparison analysis was conducted to investigate the difference between the groups. The values of HHS were significantly increased from the preoperative period to the final follow-up. Conclusions. The LD and S groups had comparable functional outcomes one year postoperatively. However, the S group was associated with worse intraoperative outcomes than the LD group.