We describe the evaluation of a participatory, garment factory-based intervention to promote gender equity. The intervention comprised four campaigns focused on gender and violence against women, alcoholism, sexual and reproductive health, and HIV/AIDS, which were implemented using information displays (standees and posters) and interactive methods (street play, one-to-one interactions, experience-sharing, and health camps). Each campaign lasted six days and the entire intervention was implemented over 10 months. We evaluated the intervention using a quasi-experimental design in which one factory served as the intervention site and a second as a delayed control. Two mobile-phone-based cross-sectional surveys were conducted at baseline and 12 months with separate systematic random samples of employees from each site. Data on socio-demographic characteristics and knowledge and attitudes related to gender equity, intimate partner violence (IPV) and alcohol use were assessed, and differences in these variables associated with the intervention were examined using difference-in-difference estimation. Analyses of data from 835 respondents revealed substantial, statistically significant improvements in attitudes related to gender equity, unacceptability of IPV, and awareness of IPV and alcohol-related support services. In conclusion, our study offers compelling evidence on the effectiveness of workplace-based interventions in advancing gender equity.