Lives of Eminent Philosophers, was written in Greek and professes to give an account of the lives and sayings of the Greek philosophers. The work doesn't have an exact title in the manuscripts and appears in various lengthy forms.

Although it is at best an uncritical and unphilosophical compilation, its value, as giving us an insight into the private lives of the Greek sages, led Montaigne to write that he wished that instead of one Laertius there had been a dozen. On the other hand, modern scholars have advised that we treat Diogenes' testimonia with care, especially when he fails to cite his sources: "Diogenes has acquired an importance out of all proportion to his merits because the loss of many primary sources and of the earlier secondary compilations has accidentally left him the chief continuous source for the history of Greek philosophy."