Imam Khomeini's struggle against Pahlavi's regime was founded on numerous jurisprudential bases, an important one of which is commanding good and forbidding evil. In this article, first the jurisprudential explanation of commanding good and forbidding evil from Imam Khomeini's viewpoint has been offered and then, a historic-analytic approach has been applied to find examples in his stances from 1960s to the victory of Islamic revolution of Iran. With a critical approach toward the individual viewpoint dominating jurisprudence, Imam Khomeini examines commanding good and forbidding evil with a social perspective. Therefore, he thinks of a broader meaning for "good" and "evil". He thinks of "implementation of justice" as the most important "good" and "the ruling of a tyrant" as the greatest "evil".