Previous studies have shown that prevalence rates among youths may be inflated due to a problem in understanding the questions of the SOGS-RA and DSM-IV-MR-J. This article reports another reason why prevalence rates of pathological gambling among youths may be inflated. In 1992, Fisher proposed 9 criteria (the DSM-IV-J) for diagnosing pathological gambling among youths, and formulated 12 questions (the Test questions) to identify the presence of these criteria. An analysis of a sample of studies using the DSM-IV-J reveals that some researchers have incorrectly used the 12 Test questions instead of the 9 criteria, which may have led to overestimated prevalence rates among youths. Other measurement issues may also be contributing to the overestimation of problem gambling in young people. The methodological implications of these issues are discussed.