Portuguese stress has been the focus of numerous studies in the past fifty years. Although studies have adopted different theoretical frameworks, from rules to grids to constraints, most of them assume a categorical view of the phonological grammar. During the same period, however, phonology as a whole has become increasingly probabilistic. In this chapter, I argue that a probabilistic approach is not only advantageous, but necessary to account for the observed patterns in Portuguese stress. Crucially, I show that such an approach is more accurate and more motivated empirically than a categorical approach.