The aim of the study was to develop a prematurity score model for predicting morbidity in premature infants in the neonatal period. Material and methods. To build an analytical model, such parameter as gestational age is used, measured in weeks with the range of changes in the score between 0 to 10, where a score of 38 - 40 weeks should correspond to 0 points, i.e., at this gestational age, the morbidity rate due to morphological immaturity of organs and systems is minimal, because by this gestational age the organ development is almost completed. The maximum score is 9.9, at gestational age of 22 weeks, which is associated with severe morphological immaturity and, therefore, high morbidity in a premature infant. Results. Based on mathematical calculations, we built a model of prematurity score, which helps estimate the degree of abnormality of a premature baby depending on gestational age. The lower it is, the higher is the score of prematurity and the likelihood of morbidity due to morphological immaturity of organs and systems. Conclusion. The proposed analytical model of prematurity score can be used to uniformly assess the prematurity factor in order to further determine the medical strategy. The model can be effectively used in scientific research and to identify statistically necessary relationships in a wide variety of studies. The main value of the model lies not in obtaining specific numerical values, but in the suggested analytical relationship reflecting the degree of morphological maturity and allowing probability estimation of the newborn morbidity.