To explore the application of B-ultrasound monitoring plus gastric insufflation for nasointestinal tube indwelling in critical neurosurgical patients.A total of 96 critical comatose neurosurgical patients indicated for nasointestinal tube indwelling were randomized into three groups of routine (A, n = 32), gastric insufflation (B, n = 31) and B-ultrasound monitoring plus gastric insufflation (C, n = 33). And the position of nasointestinal tube was observed within 24 h and at 72 h in three groups.The general profiles of three groups showed no significant differences (P > 0.05). The proportions of nasointestinal tube passing pylorus within 24 h in three groups were 43.8%, 74.2% and 93.9% respectively. Comparing group C with groups A and B, the differences presented statistical significance. The proportions of nasointestinal tube passing pylorus at 72 h in three groups were 68.8%, 83.9% and 100% respectively. Comparing group C with groups A and B, the differences had statistical significance.Refined method of nasointestinal tube indwelling and B-ultrasound monitoring may boost the rate of successful indwelling.It is worth wider promotion and application.