Although previous research indicates that audio computer-assisted self-interviewing (ACASI) yields higher reports of threatening behaviors than interviewer-administered interviews, very few studies have examined the potential effect of the gender of the ACASI voice on survey reports. Because the voice in ACASI necessarily has a gender, it is important to understand whether using a voice that is perceived as male or female might further enhance the validity associated with ACASI. This study examines gender-of-voice effects for a set of questions about sensitive behaviors administered via ACASI to a sample of young adults at high risk for engaging in the behaviors. Results showed higher levels of engagement in the behaviors and more consistent reporting among males when responding to a female voice, indicating that males were potentially more accurate when reporting to the female voice. Reports by females were not influenced by the voice's gender. Our analysis adds to research on gender-of-voice effects in surveys, with important findings on measuring sensitive behaviors among young adults.