Background: Hyaline membrane disease, often known as respiratory distress syndrome, affects premature infants nearly exclusively. The newborn's gestational age is inversely associated to the prevalence and severity of respiratory distress syndrome. Objective: The aim of this study was to predict fetal lung maturity using a non-invasive method, which is transabdominal ultrasound evaluation of thalamus echogenicity. Patients and method: This Cross-sectional prospective study included a total of 50 pregnant women, attending for antenatal care at Department of Ultrasound and Feto Maternal Unit, Zagazig University Hospitals. Scanning with transabdominal 2D ultrasound (Voluson 730 pro V 2D GE), was done to measure the biparietal diameter and the state of echogenicity of the thalamus was recorded as echogenic or echolucent, in addition to amniotic fluid particles (vernix) and the placental changes. Results: The four ultrasound parameters of lung maturity were increased with gestational age, and the presence of vernix in the amniotic fluid showed the highest and more predictive percent compared to the others, while the feature of echogenic thalamus demonstrated relatively lowest value. Conclusion: It could be concluded that evaluation of echogenic thalamus by ultrasound at the level of the biparietal diameter (BPD) is of value and can be considered as a new marker of fetal lung maturity.