This paper uses retrospective data from the ISSP98 database to reconstruct church-attendance trends in Spain from 1930 to 1992. Time series analysis is performed to examine religious changes in two parallel ways: first, to determine both male and female church-attendance trends and second, to study the gender effect, that is, differences between males and females regarding church attendance. Our results indicate that: i) both male and female church attendance is declining at a rate of 2% annually; ii) gender differences remain unaltered for the period analyzed.