Research suggests that organizational structure can influence the ability of actors to discriminate. We examine whether the structure of state legislatures affects observed discrimination in correspondent audit studies. We find that increased legislative professionalization is associated with reduced discrimination against racial minorities. By analyzing thousands of emails collected in a prior study we find that legislative professionalization is related to a higher likelihood that staffers respond to email contacts and staffers are less likely to discriminate against racial minorities across multiple measures of discrimination. Our findings emphasize the importance of substantively-relevant heterogeneity in audit studies and identify a potential mitigator of discrimination – legislative professionalism. Our results also highlight the importance of staffers in representation and the legislative process.