Objective: To study the influence of mouse nerve growth factor (mNGF) combined with hyperbaric oxygen on serum cytokines and cognitive function in patients with delayed encephalopathy after carbon monoxide poisoning (DEACMP). Methods: A total of 218 patients with DEACMP who were treated in our hospital between June 2012 and September 2016 were chosen as research subjects and retrospectively divided into the control group (n=100) who underwent hyperbaric oxygen treatment and the observation group (n=118) who underwent mouse nerve growth factor combined with hyperbaric oxygen treatment. Serum contents of nerve injury indexes and inflammatory mediators were compared between two groups of patients, and cognitive function was assessed. Results: Before treatment, differences in serum levels of nerve injury indexes and inflammatory mediators, total MMSE score and each dimension score were not statistically significant between two groups of patients (P>0.05). After treatment, serum contents of nerve injury indexes creatine kinase-BB (CK-BB), neuron-specific enolase (NSE), S-100β protein (S-100β) and lactate (Lac) in observation group were lower than those in control group; serum contents of inflammatory mediators interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-18 (IL-18), hypersensitive C-reactive protein (hs-CRP) and tumor necrosis factor α (TNF-α) were lower than those in control group; total MMSE score and each dimension score were higher than those of control group (P<0.05). Conclusions: mNGF combined with hyperbaric oxygen treatment of DEACMP is helpful to reduce the nerve injury and systemic inflammatory response, and improve the cognitive function.