This field study of 441 full-time employees in 95 work groups examined voice behavior (constructive challenge to the status quo with the intent of improving the situation rather than merely criticizing) as a function of person-centered (satisfaction with the work group, global self-esteem) and situational factors (group size, self-managed vs. traditional style of management). Using a measure of voice with demonstrated construct validity, the study showed that these person and situation factors explained 10% of the variance in peer-rated voice assessed 6 mo later. Significant Person× Situation interactions suggested that individuals with low global self-esteem or high satisfaction with their group were more responsive to the situational factors than individuals with high global self-esteem or low satisfaction. The authors discuss the importance of including person-centered characteristics, situational factors, and their interactions as predictors of voice.(PsycINFO Database Record (c) 2016 APA, all rights reserved)