Sexism is an increasingly prevalent problem in the gaming community. However, until now, assessment instruments focused on the construct “sexism against women gamers” are lacking. We present an eight-item self-report scale: Sexism Against Women Gamers Scale (SAWGS). We studied the reliability and validity of the scores of Spanish and English versions across five independent samples ( N = 2,437), with participants from Spain and the United States. Scores on both versions demonstrated high reliability, while exploratory and confirmatory factor analyses supported their unidimensional structure. The analysis established configural, metric, and scalar invariance across gender. SAWGS was invariant at the configural level across countries. SAWGS scores were independent of social desirability, positively correlated with myths about intimate-partner violence against women, sexism, and social dominance orientation, and correlated negatively with feminism. Using two fictitious scenarios of sexism in online gaming, we found that gamers with higher scores on SAWGS showed a greater tendency to downplay a sexist incident and proposed a less severe punishment for toxic gamers. The SAWGS explained additional variance on responses to scenarios beyond that explained by other measures. The detection of sexism should make it possible to develop programs for its eradication and avoid negative consequences for women gamers. Additional online materials for this article are available on PWQ's website at http://journals.sagepub.com/doi/suppl/10.1177/03616843231162837