This paper is divided into two parts. The first part will outline some elements of a semiotic theory of the brand. In the definition of the brand identity, a crucial point is an identification of basic values and the distinction of these from a more superficial brand's elements. This distinction is particularly relevant in order to pilot the brand evolution over time. A precise approach for spotting the brand's basic values will be described in this part. In the second part a specific methodology, called "Brand Audit" will be presented. The Brand Audit is a research procedure designed to help the strategic marketing of a given brand. It is based on five types of information. The brand communication universe, the company's culture and objectives, the socio-cultural trends, the market data, and the consumers' responses are investigated and put together, in order to collect several different versions of the identity of the studied brand. These five types of information are in constant interaction and evolution and must be apprehended within a unique theoretical and methodological framework.