This paper deals with the research of natural population growth and the impact of modernization processes on socio-demographic determinants of the population in the parish of Svetvinčenat from 1909 to 1918. The main part of the paper, divided into three main content parts, is the data obtained from the analysis of data from the registers of baptisms, marriages, and deaths. In addition to a ten-year data analysis, comparative data from the peacetime period, from 1909 to 1913 and the five-year period of the First World War are analyzed, during which, in addition to recruiting and requisitioning crops and livestock, the parishioners of Svetvinčenat were included in the evacuation order in May 1915. In addition, Istria, and thus the parish of Svetvinčenat, was hit in 1917 by one of the most severe droughts of the 20th century. In addition to analyzing the impact and dynamics of changes in the natural population growth under the influence of unfavorable, extraordinary circumstances, the paper also analyzes the peculiarities at the level of micro-locations (settlements) of the parish. The research is based on the registers of the baptized, married, and deceased, the Status animarum 1910 of the parish of Svetvinčenat, and the List of Losses (Verlustliste) – periodical publication of the Imperial and Royal Ministry of War of the Austro-Hungarian Monarchy.