Black, Hispanic, and Asian individuals, the three largest US racial/ethnic minorities, continue to suffer disproportionately from breast, cervical, and colon cancers largely because cancer screening continues to be underutilized even after decades of availability. This study examined the utility of theoretically grounded and culturally adapted in-person theater monologues aimed at promoting early detection screening among the three highest population racial/ethnic groups in Harris County, Houston, TX. Nine monologues were created to promote cancer screening and early detection for breast, cervical, and colorectal cancers in three different languages (English, Spanish, Vietnamese) and targeting underserved Black, Hispanic, and Vietnamese adult Harris County residents. From January 2014 to March 2020, 265 live monologue outreach events were held with 110 focused on prevention and screening for breast cancer, 75 for colorectal cancer, and 80 for cervical cancer. A total of 5989 individuals attended these outreach events and 86.3% completed the post-performance evaluation survey. Overall for all monologues, 6.6% of participants reported a positive change in their intent to screen from 75.7 to 82.3% after intervention (p < 0.001) and audience member scores on knowledge questions for all three cancers were mostly positive. Importantly, early detection questions for all three cancers were over 90% correct for all respondents, and well over 70% for the various groups. The findings revealed opportunities for improving monologue content to cultivate cancer early detection and screening knowledge. Results suggest that a theater-based approach may be an effective strategy to disseminate cancer screening education, improve knowledge, and increase intent to obtain screening among medically underserved communities.