Objective To investigate the clinical effects of naloxone hydrochloride for patients with medium-heavy craniocerebral injury. Methods 124 patients with medium-heavy craniocerebral injury enrolled in our hospital were randomized into Treating group and control group evenly, and two groups showed no difference in ages, lesional location, Glasgow coma scale and surgical procedure between. Patients in control group received symptomatic treatment and conventional operation of reducing intracranial hypertension, cleaning hematoma or decompressing bone flap while victims from control group were subjected to a additional administration of naloxone hydrochloride (0. 3mg/kg/d · 7 d ). The variance of intracranial tension and prognosis were observed. Results The intracranial tension of control group in the 3rd, 5th, 7th days were (2.86 ± 0.34) kPa, (2.51 ± 0.39) kPa, (2.26 ± 0.38) kPa respectively, while Treating group were (2.48 ± 0.40) kPa, (2.21 ± 0.44) kPa, (2. 10 ± 0.38) kPa which were significantly lower than the corresponding period of Control group (all P < 0.05 ). Prognostically, the cases with outcome of favorable prognosis, death, medium handicap or severe handicap in treating group were 38, 13, 5, 6, which were markedly better than treating control group (21, 19, 9, 13 cases, respectively; P < 0.05). Conclusion Based on traditional comprehensive therapies including operation, dehydrating drugs, mild hypothermia, anticovulsants and neural nutrition medicine, naloxone hydrochloride could further alleviate the intracranial hypertension, improve the prognosis of patients with medium-heavy craniocerebral injury and presented with high clinic value. [ABSTRACT FROM AUTHOR]