This study evaluates consumer preferences in three Spanish cities (Barcelona, Zaragoza y Pamplona) with the objective to estimate the relative importance of beef attributes including its enrichment with omega-3 (n-3) fatty acids and conjugated linoleic acid (CLA). The impact of sensory evaluation on consumer preferences that differed in the received information, and on the unobserved heterogeneity of the scale factor and the attributes, was also evaluated. Data were collected from a structured and self-completed questionnaire in a controlled environment, tasting 4 different meat samples in the three cities (647 consumers total). The choice experiment, analyzed with the Generalized Multinomial Model (G-MNL), was applied before and after consumer evaluation of the acceptability of enriched beef. Results showed a significant impact of the sensory evaluation on consumer preferences, which was differentiated by the received information. The utility of n-3 enriched beef in the three cities increased significantly after beef tasting, especially for uninformed consumers, whereas the utility of CLA enriched beef was not significant. Scale heterogeneity (variation of the degree of randomness on decision making) decreased significantly after the sensory evaluation. Results showed an increase in the overall acceptability of n-3 or CLA enriched beef relative to conventional beef, and the received information by consumers did not alter significantly their sensory scores.