Condom use during last sexual contact is a survey measure that may be used to inform monitoring and evaluation indicators of recent condom use in populations at risk for HIV infection and other sexually transmitted infections, such as the uniformed services. The authors tested for differences in condom use measures that were fielded within separate Biological and Behavioral Surveillance Surveys conducted in the armed forces of two separate nations: the Dominican Republic and Belize. Both surveys included measures of condom use during last sexual contact with specified partners and both surveys included the Risk Behavior Assessment (RBA), which measures specific sexual acts and condom use frequency during a specified time period. In both samples, more than 40% of respondents who reported condom use during last sexual contact with a regular partner also reported engaging in unprotected sex when screened with the RBA. Furthermore, more than 60% of respondents who reported condom use during last sexual encounter with a commercial sex worker also reported engaging in unprotected sex when screened with the RBA. The results carry implications for monitoring and evaluation indicators of large-scale HIV prevention programs. The authors recommend that, when feasible, more in-depth instruments such as the RBA be considered to measure recent condom use in populations of uniformed services personnel.