This research study tries to develop a descriptive, empirical and target-oriented approach in the field of audiovisual translation by focusing specifically on translation norms. Two versions of an American film are analysed; by gathering microtextual samples of both the Spanish-dubbed and Spanish-subtitled translated versions, each of the two translated samples is then compared with the same element in the original English version. The comparison is made on the basis of a methodological framework developed specifically for the study, consisting of a three-parameter model, the parameters being translation norms, audiovisual translation constraints and translation techniques. The final conclusions of the study, based on quantitative results, indicate that dubbing is subject to more constraints than subtitling, and that the so-called 'formal constraints' are present in both translated versions. As far as norms are concerned, 'linguistic standardization' and 'secondary norms' are identified as the most frequent ones. Additionally, the results show that dubbing tends to use 'domesticating' translation techniques, while subtitling tends to use a more 'foreignizing' approach.