Objective To compare the clinical efficacy of direct anterior approach (DAA) and posterolateral approach (PLA) in primary total hip arthroplasty (THA).Methods We collected and retrospectively analyzed the clinical data of 285 patients undergoing primary unilateral THA in our department from January 2016 to July 2019, including 100 cases of DAA and 185 cases of PLA. The blood loss, operative duration, Visual Analogue Scale (VAS) score, Harris Hip Score (HHS), and the range of motion (ROM) of hip joint (flexion, extension, adduction, abduction, internal rotation, and external rotation) were observed and analyzed.Results The total blood loss, hidden blood loss, and the percentage of hidden blood loss in DAA group were significantly less than those in PLA group (P < 0.05). The operative duration and straight leg raise time were shorter in DAA group compared with PLA group (P < 0.05). The repeated measures analysis of variance exhibited that: ①The HHS, VAS score, and ROM of hip joint were different among time points (P < 0.05); ②There were differences in HHS and VAS score (P < 0.05) rather than ROM of hip joint (P > 0.05) between the groups; ③The change trend of HHS and VAS score (P < 0.05) instead of ROM of hip joint (P > 0.05) differed between the groups.Conclusions Compared with PLA, applying DAA for primary unilateral THA can effectively reduce perioperative blood loss, shorten the operative duration and decrease postoperative pain, which is conducive to early functional recovery.