Objective To systematically review the efficacy of hydromorphone hydrochloride injection for treatment of chronic pain.Methods Web of Science Proceedings and PubMed were searched for clinical trials involving the efficacy of hydromorphone for treatment of chronic pain, with no language or time limit.Evaluation indexes included visual analogue scale (VAS) score and the rate of pain control or relief.The studies were screened independently, and the data were extracted by two researchers.Meta-analysis was conducted using the Stata 10 software.Results Eleven studies involving 452 patients were included in our meta-analysis.VAS score was significantly decreased after treatment compared with that before treatment.For the patients with cancer pain, VAS score was significantly decreased after treatment with hydromorphone hydrochoride injection, and the rate of pain control or relief was increased when compared with the other opioid analgesics.Conclusion Hydromorphone hydrochloride injection can treat chronic pain, and it may provide better therapeutic effect than the other opioid analgesics for the patients with cancer pain.