Trademark dilution is, in a general sense, a reduction in brand equity due to the unauthorized use of the trademark by third parties (junior brands). Although there are two types of dilution, blurring and tarnishment, existing academic empirical evidence only relates to blurring cases, showing its damage to some variables related to brand associations in consumers’ minds. Literature also shows the moderating role of the similarity between junior brands, but this evidence is not complete unless presumable tarnishment cases are analyzed. This paper compares the effect of two types of junior brands over strength of associations and brand equity of famous trademarks. An experimental approach was applied with a sample of 372 undergraduate students, users of two famous convenience brands. Junior brands use identical or similar famous brand names in different product categories, offering a co...