Among other regulatory requirements, medicine brands should be composed of single names without abbreviations to prevent errors in prescription of medication. The purposes of the study were to investigate the compliance of a sam ple of Portuguese medicine brand names with Portuguese pharmaceutical regulations. This includes identifying their basic linguistic characteristics and comparing these features and their frequency of occurrence with benchmark values of the colloquial or informal language. A sample of 474 brand names was selected. Names were analyzed using manual (visual analyses) and computer methods (FreP - Frequency Patterns of Phonological Objects in Portuguese and MS word). A significant number of names (61.3%) failed to comply with the Portuguese phonologic system (related to the sound of words) and/or the spelling system (related to the written form of words) contained more than one word, comprised a high proportion of infrequent syllable types or stress patterns and included abbreviations. The results suggest that some of the brand names of Portuguese medication should be reevaluated, and that regulation on this issue should be enforced and updated, taking into consideration specific linguistic and spelling codes.