Abstract: This dissertation deals with the advantages and tools supplied by new technologies nowadays. More specifically, the study analyses the use of online dictionaries for the learning and the study of new languages (L2). It reports the results of a research on how advanced language learners use online dictionaries and to what extent they take advantage of all the resources those provide. The data was collected through questionnaires given to 3rd and 4th grade students of the degree in English Studies at the University of Zaragoza. The results revealed how they use online dictionaries and what they think about them, they showed that advanced students still underuse online dictionaries for pronunciation, phonetic and grammatical tasks, although online dictionaries provide a wide range of tools for helping learners in all kind of tasks such as reading or writing. Most of them only use them for translating a word or finding its meaning. For these reasons I proposed a dictionary workshop involving different skills for making students aware of the different possibilities online dictionaries provide.