Objective To explore the incidence and influencing factors of low birth weight in infants in high altitude areas. Methods A total of 340 live births delivered in the People’s Hospital of Anduo County, Xizang (with an average local altitude of 5 200 m) from Apr. 2022 to Apr. 2023 were enrolled, and the incidence of low birth weight was recorded. The effects of maternal general information, pregnancy and perinatal complications, and serum levels of 5 metal elements (calcium ［Ca］, iron ［Fe］, magnesium ［Mg］, zinc ［Zn］, and copper ［Cu］) in the third trimester of pregnancy on the incidence of low birth weight were analyzed. Results The incidence of low birth weight was 18.24% (62/340). The incidence of low birth weight in infants had no relation with maternal age, pregnancy times, parity, body mass index at the beginning of pregnancy, adverse pregnancy history, gestational diabetes mellitus or neonatal gender. The incidences of low birth weight in mathers with gestational hypertension, gestational intrahepatic cholestasis, gestational anemia, premature rupture of membranes, oligohydramnios, and preterm birth were significantly higher than that in mothers without the above symptoms (all P＜0.001). The maternal serum levels of Ca, Fe, Mg, Zn, and Cu in the third trimester of pregnancy of the low birth weight group were significantly lower than those in the non-low birth weight group (all P＜0.001). Multivariate logistic regression analysis showed that gestational hypertension, gestational intrahepatic cholestasis, premature rupture of membranes, premature birth, maternal serum Ca, Zn, and Cu levels were the influencing factors of the low birth weight (all P＜0.001). Conclusion The incidence of low birth weight in infants in high altitude areas is affected by gestational hypertension, gestational intrahepatic cholestasis, premature rupture of membranes, and premature delivery, and it is also related to the maternal serum levels of Ca, Zn and Cu in the third trimester of pregnancy.