This paper revisits monopolists' profit tax evasion by taking corporate social responsibility into account. It is shown that: (i) the monopolistic firm's evasion and production decisions are complements in the Edgeworth sense; (ii) the deterrent effects of the penalty rate and the audit probability on tax evasion are ambiguous when monopolistic firms possess a social responsible motive; and (iii) an increase in the monopolistic firm's social responsibility leads to decreases in both its output production and tax evasion.