The document analyses the impact of brand relationship quality and naming strategies on the success of brand extension through research based on an experimental 2x2x2 design. The independent variables taken into consideration are: the perceived fit between the product categories involved in the decision to expand (high vs. low); the name chosen for the new product (predominance of the parent brand vs. sub-brand); the level of brand relationship quality (high vs. low). The dependent variable object of analysis is the consumers’ evaluation of the expansion. The results show that in the presence of high brand relationship quality, the consumers value extension more favourably, no matter what the level of category fit. However, in situations of high (low) category fit and high brand relationship quality, the evaluation of the extension is better if the predominance of the parent-brand (sub brand) is greater in the naming of the new product. If the brand relationship quality is low, the consumers’ evaluation is not influenced by the naming strategies.