Objective: To assess whether ultrasound-guided intercostal nerve block improves analgesia in acute herpes zoster (AHZ) and reduces the risk of postherpetic neuralgia (PHN). Methods: A total of 80 patients with acute herpes zoster were enrolled and randomized into a control group (valacyclovir plus gabapentin, n=40) and an experimental group (the same regimen combined with ultrasound-guided intercostal nerve block, n=40). NRS scores were assessed before treatment and at 1 week, 1 month, and 3 months after treatment; PSQI scores were assessed before treatment and at 1 month and 3 months after treatment. The incidence of PHN at 3 months was compared between the 2 groups. Results: NRS scores at 1 week, 1 month, and 3 months after treatment were lower than baseline in both groups (P<0.05). PSQI scores at 1 month and 3 months after treatment were also lower than baseline in both groups (P<0.05). At the same time points, the experimental group showed lower NRS and PSQI scores than the control group (P<0.05). The incidence of PHN was lower in the experimental group than in the control group during the 3-month follow-up period (P<0.05). Conclusion: Compared with standard antiviral and gabapentin therapy alone, adding ultrasound-guided ICNB provides better pain relief in AHZ, improves sleep quality, and may reduce the risk of PHN within 3 months.