The current study examined the extent to which the presence of misogynistic peers, relative to a non-misogynistic peers, obstructs bystander intervention behavior for sexual aggression among men, and how men’s tendency to appraise as stressful situations that conflict with traditional male gender norms (i.e., masculine gender role stress; MGRS) influences state fear following an audience manipulation and inhibits bystander behavior. Undergraduate men completed a novel laboratory paradigm for bystander intervention for sexual aggression. Data provided support for some, but not all hypotheses. Findings indicated (1) the presence of misogynistic peers increased the odds of not intervening in SA and (2) higher levels of MGRS significantly increased the rate of bystander behavior among non-misogynistic, but not misogynistic, peers. Clinical and research implications are discussed.