The historic settlement of Hallstatt (Austria) was eminently Catholic until the 16th century when Lutheranism was introduced in Austria during the Reformation. From this moment both churches coexist and generate registers for baptisms, weddings and funerals. In this way data for Catholic and Protestant genealogies become a worthy tool to assess LHT for a period comprising 128 years (18th-20th centuries), supposing four generations of parishioners for every faith. Since a variety of studies prove religion influences individual fitness, these data are statistically processed by SPSS in order to test differences in LHT for both faiths, paying attention to those related with fitness, i.e., LRS, LS and Offspring, according to main splits by religion and sex. Basing on seven LHT, i.e., ABF, ABL, IS, LRS, LS, Offspring and RS significant differences are obtained for four of them. A latter analysis links these peculiarities to a variety of living standards each religious population experiences. In the specific case of the Protestant collective an advantageous fitness is configured. In addition, early demographic transition for Austria constitutes an aspect to pay attention to. Comparing to other researches this one presents a better fitness for Protestants probably due to a higher standard living. Future studies are considered by processing the data base by cohorts and comparing with another historic populations to check consistency.