For a long time, the exact nature of Περὶ βίων literature and its relation to biography has been debated. Scholars have considered such works collections of biographies or philosophical treatises on the right way of life. This paper studies all extant fragments across various philosophical schools. Epicurus and Chrysippus seem to have given practical instructions on the right lifestyle. Clearchus, Dicaearchus and the imperial writers Timotheus and Seleucus, by contrast, took a more anecdotal approach. However, the fragments do not support a reconstruction of biographies in the sense of a description of the life of an individual from birth to death. The anecdotes in Clearchus were probably moralising exempla. Moreover, not all biographical fragments of Dicaearchus necessarily belong to his work On Lives. I also argue that Περὶ βίων works were probably the ideal place for debate and polemic against competing schools.