The goal of this paper is to offer an analysis of polysemy and related semantic relations emerging in prepositions belonging to Aquilan, a dialect of Italian. The data are based on fieldwork research, in which different polysemy tests where used in an experimental setting. Two key results emerged from the study. First, Aquilan prepositions display a degree of polysemy inversely proportional to their morphological complexity, with some prepositions being monosemous (e.g. a, a destra de, ‘ngima a). Second, prepositions’ senses can stand in relations of colexification, partial synonymy, or hyponymy. Colexification holds when related senses become part of a preposition’s sense range; hyponymy and partial synonymy (overlap) when one preposition denotes all or some of the places denoted by a second preposition. The work thus offers a paradigmatic view of the polysemy of Aquilan prepositions that sheds light on seldom attested polysemy patterns, and contributes novel insights on the ongoing debate on this phenomenon.