The study of the adjectives derived from anthroponyms in Spanish language reveals a clear preponderance of the suffixes -ano and -ista, which, however, have different history, meaning, distribution and denotative variation. The suffix -ano, which inherits the relational value of Latin -anus, has been the most historically used to form adjectives, both demonyms and deanthroponyms. The suffix -ista, of Greek origin and much more specific meaning (‘follower of’), has only known a great expansion in the last two centuries and very rarely has been used to form demonyms. In this contribution we will focus on -ano and, from a semantic idiomatic perspective, we will make some linguistic considerations about the proper name, the differences between the detoponymic and deantroponymic relational adjectives, the adjectival derivation with the suffix -ano and its variants in Spanish language in relation to the concurrent suffixes when it is attached to anthroponyms; at last, we will give account of its most frequent lexical variation.