The work presented in this article is part of a wide-ranging and ambitious project, started few years ago, to study the role of astronomy in Roman urban layout. In particular, the main aim is to check whether Roman cities present astronomical patterns in their orientations. The project emerged from ideas on how to properly orientate the main streets of a Roman town, as attested in a number of ancient texts and later discussions led by contemporary scholars. We present here the final conclusions of a particular study developed in the Iberian Peninsula (Roman Hispania), where the urbanism that we tend to characterize as properly Roman flourished during both the Republic and the Empire. The sample analysed includes 81 measurements of Roman urban entities spread throughout the Iberian Peninsula and is the largest dataset obtained in a specific region so far. Our results present suggestive orientation patterns that seem to point towards an astronomical intentionality.