Objective To compare the clinical efficacy of proximal femoral nail antirotation (PFNA) and InterTan nail in the treatment of unstable femoral intertrochanteric fractures in elderly patients. Methods Totally 102 elderly patients (≥65 years old) with A2.2, A2.3 and A3 type unstable femoral intertrochanteric fractures were enrolled in this prospective study. The patients were divided into PFNA group (n=48, with a mean age of [75.6±6.7] years) and InterTan group (n=54, with a mean age of [75.3±6.6] years) according to the surgical method. During follow-up, the Harris hip score was recorded at the last outpatient review, and the survival information of patients was obtained by telephone interview and census register database. Results There was no significant difference in baseline characteristics of patients between the two groups. The operation time, intraoperative fluoroscopy time and bleeding volume of patients in the InterTan group were significantly higher than those in the PFNA group (P<0.05). There was no significant difference in hospital stays or postoperative spikes between the two groups (P>0.05). Screw cut-out occurred in 4 patients in the PFNA group, and the hospital death occurred in 3 (2.9%) patients in the two groups. There was no significant difference in the healing time and Harris hip score between the two groups during follow-up (P>0.05). The median survival time of patients in the PFNA group and the InterTan group was 33.9 and 27.4 months, respectively, with no significant difference between the two groups (P>0.05). Conclusion PFNA and InterTan nail have similar therapeutic effect on elderly patients with unstable femoral intertrochanteric fractures. PFNA is better in improving operation time, intraoperative fluoroscopy time and intraoperative bleeding volume, but has the risk of screw cutting-out.