Objective: To observe the effects of combined fascia iliaca compartment and ilioinguinal/iliohypogastric block guided by ultrasound on postoperative analgesia of elderly patients with total hip replacement. Methods: A total of 50 patients were selected in this study, aging from 61 to 84 years, at ASA II or III, all of whom had suffered total hip replacement via unilateral approach under general anesthesia between April 2015 and October 2015. The patients were divided into 2 groups (n=25) with the random number table: simple fascia iliaca block (simple group) and combined fascia iliacus and ilioinguinal/iliohypogastric block group (combined group). Immediately after the operation, the patients were given nerve block on the diseased lateral guided by ultrasound. The simple group was given 30 ml of 0.3% ropivacaine via fascia iliaca compartment injection, while the combined group was given 15ml of 0.3% ropivacaine each via fascia iliaca compartment and ilioinguinal/iliohypogastric injection, respectively. The patients were recorded for general conditions, resting and motion VAS scores at postoperative 6, 12, 18 and 24 h, ultrasound imaging time, puncture administration time, operation time, the cumulative dosage of sufentanil and the incidences of various adverse reactions. Results: There were no statistical differences between the two groups of patients in general condition (P>0.05) and resting pain scores at each time point after operation (P>0.05). Compared with the simple group, motion pain scores of the combined group were decreased at postoperative 6 and 12 h (P<0.05), while there were no statistical differences in motion pain scores at postoperative 18 and 24 h (P>0.05). There were no statistical differences between the two groups of patients in ultrasound imaging time and puncture administration time (P>0.05). Compared with the simple group, the combined group had longer operation time and smaller cumulative dosage of PCA sufentanil (P<0.05). There were no statistical differences between the two groups of patients in incidences of postoperative analgesia related adverse reactions (P>0.05). Conclusion: Combined fascia iliaca compartment and ilioinguinal/iliohypogastric block guided by ultrasound is safe and effective for postoperative analgesia of elderly patients with total hip replacement, which can significantly alleviate patients’ pain and at the same time reduce the dosage of fentanyl.