Purpose From an integrated marketing communications perspective, this study aims to analyse what level of consistency among brand messages is more effective in terms of customer‐based brand equity. In particular it aims to evaluate its impact on brand knowledge structure, and how brand familiarity moderates this influence. Design/methodology/approach A sample of 194 subjects participated in a between subjects experiment. An integrated communication campaign composed of two different tools (advertising and nonmonetary promotion) was assessed by individuals. Brand familiarity (familiar brand vs unfamiliar brand) and consistency among messages (high vs moderate) were manipulated to test a set of hypotheses. Findings Results show that the effectiveness of consistency among messages depends on brand familiarity. For familiar brands moderately consistent messages improve their awareness (recall), enrich their network of associations, and generate more favourable responses and brand attitudes. However, for unfamiliar brands, no significant differences are found between high and moderate levels of consistency, except for brand recall, being higher when highly consistent messages are used. Research limitations/implications Limitations of the study are those typically associated with the experimental methodology. Specifically, a single product category and only two communication tools were used in the experiment which may limit the generalisability of the results. Practical implications For unfamiliar brands, brand managers should focus on consistent brand messages to build awareness for these unknown brands. By contrast, for familiar brands the goal of the communication strategy must be to revive the interest in them through moderate consistent messages that can excite consumers and make them think again about these brands. Originality/value The originality of this study resides in incorporating the newest approach of communication management (integrated marketing communication or IMC) to illustrate how consistency among messages could be used to build the type of brand knowledge structure that nurtures brand equity. Furthermore, compared to previous studies of IMC, which have addressed this issue under a merely conceptual perspective, this paper offers empirical evidences using a more practical perspective and focusing on managing brand knowledge structures as a way for improving brand image.