Nowadays, there is a wide debate about what rural means. An operational definition of rural concept is essential in order to measure health problems, optimize resource allocation and facilitate decision making aimed at closing the gap on inequity between areas. In 2005, the rurality index for Small Areas in Spain (IRAP) was developed using the 1991 Census of Population data. Nevertheless, the concept and definition of rurality may evolve through time. In order to capture these changes, the variables used to make up the rurality index should be reviewed and updated periodically. Along these lines, and within the context of the rural-urban continuum, the aim of this paper is to replicate and update the IRAP using the data provided by the 2001 Census of Population, as well as to describe the changes in rurality observed in each municipality between 1991 and 2001. The index was updated on a Principal Components Factor Analysis, giving rise to a single factor that is correlated to the aging of the population, economic dependency, farming, livestock or fishing-related employment, self-employment, second dwelling ratio, population density, immigration and perception of noises and atmospheric pollution in the surroundings of the residential area. Most variables that made up the 1991 IRAP remain as important components of the 2001 index, indicating the robust nature of the measure. Only 10% of the Spanish municipalities have changed their rurality status between the two Censuses. The 2001 rurality index can be considered a good updated approach to the concept of rurality in Spain as well as an important criterion to social policies.