This study aims to assess the accuracy of maternally perceived birth size and its associated factors among the Syrian refugees in Turkey, using the data from 2018 Turkey Demographic and Health Survey Syrian Migrant Sample (TDHS-SM-18). The study includes information on the last-born child, singleton pregnancies, births in healthcare facilities, children under 5 living with their mothers, with recorded birth weight (n = 969). The study categorizes the mother’s perception of size into three groups : compatible, overestimated, and underestimated. Various factors, including sociodemographic characteristics, financial aspects, maternal characteristics, and child characteristics, are considered as explanatory variables. The analysis employs a complex sample multiple logistic regression model. The findings reveal that the majority of mothers accurately perceive the birth size, but 17.1% of them do not. Maternal factors such as region of residence, literacy, occupation, age at birth, and child factors such as birth order, birth interval, gender, and birth weight are identified as associated factors with maternal misperception. This study provides valuable insights into the accuracy of maternally perceived birth size and sheds light on the factors influencing this perception among Syrian refugee mothers in Turkey.