Objective To preliminarily explore the possible effect of betahistine on body weight and lipid metabolism in male schizophrenics treated with olanzapine. Methods A total of 41 male patients with schizophrenics hospitalized in Beijing Huilongguan Hospital from September 2020 to September 2021 were selected. A 4-week open-ended trail were carried out with additional betahistine 16 mg， 3 times per day， based on single drug treatment with olanzapine for 4 months and over. Fasting full blood examination， fasting blood sugar， triglyceride， total cholesterol， liver function and other indicators were tested at baseline and the end of 4 weeks' treatment. At the same time， fasting weight， height， abdominal circumference， and blood pressure were measured， and body mass index （BMI） were calculated. Clinical symptoms were assessed at baseline and over 4 weeks using the Positive and Negative Symptom Scale （PANSS）. The results of each index before and after the test were statistically analyzed by paired-sample t test. Results After 4 weeks of betahistine intervention， patients' body weight ［（70.1±6.7） kg vs （71.7±7.5） kg］， BMI ［（24.7±2.1） kg/m2 vs （25.2±2.4） kg/m2 ］， and total cholesterol ［（4.3±0.8） mmol/L vs （4.6±0.8） mmol/L］ were all lower than those before treatment， and the differences were statistically significant （t=4.52，3.97，2.47； P＜ 0.05）. There was no significant difference in PANSS total score， blood routine index and alanine aminotransferase before and after treatment with betahistine （P ＞ 0.05）. Conclusions Betahistine may improve the body weight and cholesterol of male patients with schizophrenia caused by olanzapine.