In this study, a PROLOG-based computational tool designed to assign pauses in Spanish texts is proposed. Our purpose is to develop a prosodic segmentation algorithm suitable to be implemented in a text- to-speech system for Spanish. By means of the analysis of a corpus of read texts in Spanish, prosodic and syntactic factors guiding the location of orthographically unmarked pauses are identified. These factors are used to design a compu-tational model for assigning pauses in unrestricted texts. The performance of the system has been assessed by means of a comparison between its suggested segmentation and natural speech. The obtained results indicate that the system is able to capture empirical facts.