Memory about a brand is associated with memory about the category of the brand’s product (Hutchinson, 1983). Consequently, when thinking about products in that category, that brand is likely to be recalled by the activation of the associative network and to be considered for choice (Nedungadi, 1990). Therefore, the strength of mental association between a brand and its product category determines the top-of-mind accessibility of the brand in the product category and constitutes a fundamental aspect of consumer-based brand equity (Keller, 1993). Despite its importance, the structure of mental association between a brand and a product category is largely invisible in traditional behavioral measurements. We posit that mental representation for a brand and for its product category can both be directly visualized as neural representations, and that mental association between the brand and the product category can be operationally defined as the similarity of the neural representations between the brand and the product category. Furthermore, we hypothesize that neural representational similarity between brand and product category will be predictive of mental accessibility of brand assessed by behavioral measurement such as brand recall. To demonstrate our neural definition of brand-category association and to test our hypothesis about the relationship between neural similarity and mental accessibility, in an fMRI study, we recorded consumers’ brain activity in response to car brands and the concept of car in an MRI scanner as well as recorded the process of brand recall when they were cued by the product category “car” outside the scanner.