Researching female sex workers (FSWs) in Indonesia, where commercial sex tends to be hidden or undercover, is challenging but possible. This is even more challenging when it involves investigation of sensitive behaviors, such as their alcohol use, a known disinhibitor to risk behavior. The adoption of effective strategies is needed to increase response rates and improve data quality. This article describes procedures used to research FSWs' alcohol use during commercial sex in the Eastern part of Indonesia. Challenges, lessons learned, and recommendations for best practices are discussed.