Aim of study: The study was carried out to evaluate maternal lifestyle and behavioral factors affecting the risk of spontaneous PTB. Methods: A descriptive study design was done in the postnatal ward of the Obstetrics Department at Zagazig University Hospital, Zagazig City, Al Sharkia Governorate. The sample of 200 women was assigned to two groups selected through the purposive sampling method from January to September 2017. The questionnaire was designed to collect background data of women. Also, lifestyle and behavioral features of women during pregnancy period. Results: The results of the current study showed that, there were no statistically significant differences between the two groups according to their socio-demographic characteristics group (P > 0.05). However, there was a significant relation between spontaneous preterm birth and inadequate antenatal care, short inter-pregnancy interval, and lifestyle factors (P<0.001). Moreover, serious life events and vital exhaustion during their pregnancy were significant risk factors for spontaneous preterm birth. Conclusion: There is a statistically significant relationship between inter-pregnancy intervals (less than 12 months) and increased risk of spontaneous PTB. As well as, stresses of heavy and night working associated with the risk of PTB. Serious lifestyle events for pregnant women contribute to a significant increase in the risk of PTB, where Short sleep duration or prolonged, and vital exhaustion were highly associated with an increased risk of spontaneous PTB.