Among his approximately 227 works listed in Lamprias' catalog, the most well-known are the "Parallel Lives" and the "Ethics or Moralia".

In the "Parallel Lives," Plutarch narrates the heroic deeds and describes the characters of Greek and Roman soldiers, legislators, rhetoricians, and politicians.

The "Ethics" consists of a series of more than sixty essays on ethical, religious, natural, political, and literary topics. Plutarch became popular because he addressed specific human issues.

His philosophy was eclectic, as he gathered borrowed elements from the Stoics, Pythagoreans, and Peripatetics, around a Platonic core. The influence Plutarch had in later years was profound and significant.

His "Lives" inspired the orator Aristeides and the historian Arrian, while the emperor Marcus Aurelius was familiar with and read his work.