Background/Aim: Intraoperative changes in patient position or other changes that would disrupt the decisive position during preoperative preparation would directly have a negative impact on acetabular cup orientation in patients undergoing total hip arthroplasty. This study aimed to compare the standard support system and a novel lateral support system (Maltepe), which ensures stable lateral decubitus positioning during the perioperative period, in patients undergoing total hip arthroplasty with the posterolateral approach. Methods: Patients operated in our department for osteoarthritis of the hip between 2012 -2019 were included in this case-control study retrospectively. 46 and 41 patients were prepared for surgery in lateral decubitus position using the classical (Group 1) and novel (Group 2) lateral support systems, respectively. The groups were compared in terms of demographic characteristics, duration of preparation, anteversion and inclination, and Harris Hip scores. Results: Mean patient age was 66.89 (7.53). There was no significant difference between the two groups in terms of age (P=0.546), gender (P=1.00), body mass index (P=0.302) and the operative side (P=0.724). Duration of preparation and absolute deviation values from 15 degrees and 45 degrees were significantly better in group 2 compared to group 1 (P<0.01). There was no significant difference between the Harris Hip Scores of two groups. Conclusion:We demonstrated that the novel support system we developed provided more successful outcomes than the classical system in terms of acetabular cup orientation.