Objective To evaluate the effect of continuous fascia iliaca compartment block (FICB) immediately upon admission as preemptive analgesia on perioperative anxiety and sleep quality in elderly patients with femoral neck fracture (FNF) undergoing total hip arthroplasty (THA). Methods A total of 74 elderly patients with FNF, who underwent elective THA under general anesthesia, were selected. According to the random number table method, they were divided into two groups: a FICB group (group F, n=36) and a routine group (group C, n=38). Patients in group F received continuous FICB after admission, which was withdrawn after successful anesthesia induction and intubation on the day of surgery. Those in group C were routinely administered after admission with 15 mg ketorolac tromethamine through drip infusion once a day until the day of surgery. Then, the Visual Analog Scales for Anxiety (VAS‑a) scores, and the Visual Analog Scale (VAS) scores at resting and during movement were recorded at immediate admission (T0), at post‑FICB 30 min (group C at the same time point) (T1), on the morning of surgery (T2), at post‑operation 6 h (T3), at post‑operation 24 h (T4), and at post‑operation 48 h (T5). The Leeds Sleep Evaluation Questionnaire (LSEQ) scores on the day of admission, 1 d before operation, and at post‑operation days 1‒7 were recorded. The intraoperative dosages of propofol and remifentanil, the time to first pressing of analgesic pump after surgery, the number of effective pressing within 48 h after surgery, the number of rescue analgesia cases, the incidence of postoperative adverse events [postoperative nausea and vomiting (PONV), urinary retention, and respiratory depression], and the time to first off‑bed activities were recorded. Results Compared with T0, the VAS‑a scores, as well as both resting and exercise VAS scores, were significantly lower at T1-T5 in group F and at T3-T5 in group C (all P<0.05). Compared with group C, group F had significantly lower VAS‑a scores, resting and exercise VAS scores at T1-T3 (all P<0.05); significantly higher LSEQ scores on the day of admission, 1 d before operation, and 1‒3 d after operation (all P<0.05); significantly lower intraoperative dosage of propofol and remifentanil, fewer effective presses of the analgesic pump within 48 h after surgery, and fewer patients requiring ketorolac tromethamine for rescue analgesia (all P<0.05); a significantly later time to first press of the analgesic pump after surgery (P<0.05); significantly lower incidence of PONV and urinary retention (all P<0.05); and a significantly earlier time to first ambulation (P<0.05). There was no statistical difference in other indicators between the two groups (all P>0.05). Conclusions Continuous FICB as preemptive analgesia immediately upon admission can effectively alleviate perioperative anxiety and improves perioperative sleep quality in elderly patients with FNF undergoing THA. It also reduces the use of opioids and non steroidal antiinflammatory drug, decreases the incidence of postoperative adverse events, and promotes early postoperative off‑bed activities.