The coda /s/ is the most extensively studied phonological segment in Hispanic dialectology and sociolinguistics. However, the coda /s/ in Peruvian Andean Spanish has received relatively little attention. This study examines the variation in syllables and word-final /s/ in the city of Cusco, Peru. The statistical analysis of 2400 tokens from 24 sociolinguistic interviews reveals that the Spanish of Cusco is located within the conservative dialects with the predominant use of the sibilant [s] and that coda /s/ weakening is conditioned by linguistic factors, such as word position and the following phonological context. Additionally, younger speakers and those who have higher levels of education weaken codal /s/ more frequently than older generations and speakers with lower levels of education.