The purpose of this study is to demonstrate how students at tertiary level can improve their pronunciation learning skills by using an online pronunciation tool. It will explore in depth students’ progress in English pronunciation as far as stress is concerned, this being one of the most difficult areas of English for Spanish and Catalan speakers, by creating online materials to develop their pronunciation skills. Interaction and cooperation between the learners themselves and the teacher will definitely add to the effectiveness of this project in that learners will benefit not only from the teacher’s evaluation but also from the other learners’ assessment, too. The project deals with one of the most important aspects of the pronunciation of English, word and sentence stress. In order to show the benefits of the online materials that will be developed, a study will be carried out with two groups of university students. The first group will receive instruction on English stress in a conventional manner, while the second group will make use of an online tool for learning pronunciation. It is expected that the results obtained with the second group will be significantly better than those obtained with the first. This will support to the usefulness of information technologies in the learning of English Pronunciation.