Abstract Research carried out over the past few years in several Andalusian cities has revealed the processes of convergence towards conservative realisations that are occurring among the allophones of the phoneme /θs/. This time, using the Seville PRESEEA corpus, we have analysed the frequency of the seseante and dento-interdental pronunciation patterns that coexist in this city, and we have correlated them with linguistic, social, and individual parameters. Our data showed that this variation process was mainly influenced by closeness of [s] and [θ] in the immediate phonetic context, and by the educational attainment level, the age, and the sex of the respondents. The analysis per surveyed subjects indicated that most of them combined both variants.