The factor structure, measurement invariance, validity, reliability, and stability of scores on the Brief Situational Confidence Questionnaire (BSCQ) were evaluated for use with incarcerated youth. The BSCQ is an 8-item measure that assesses self-efficacy to resist alcohol use in tempting situations. The brevity of the measure may make it a useful tool for clinicians and researchers in a forensic setting. Analyses were conducted with 2 separate samples (N = 205 and N = 189) of incarcerated youth (M age = 16.90 and 17.12 years, respectively; 88% and 86% male). Based on prior theory and confirmatory factor analyses (CFAs), results indicated that a correlated 2-factor model best fit the data. Multisample CFAs suggested that BSCQ scores demonstrated configural and metric invariance across our 2 samples. Further, the BSCQ scores demonstrated sufficient test-retest stability in Samples 1 and 2 (Pearson's r = .66, .55) and internal consistency (Cronbach's α = .84 and .86, respectively). Negative binomial regressions showed that the overall BSCQ scores were significantly associated with concurrent alcohol use (number of drinking days, number of heavy drinking days, average drinks per week) and significantly predicted future alcohol use. Scores on the BSCQ demonstrated sufficient stability, internal consistency, and validity, and the 2-factor structure was largely invariant across 2 separate samples of incarcerated youth. Given its brevity, the BSCQ may provide valid and reliable scores to use with this population when time and resources are scarce. (PsycINFO Database Record (c) 2020 APA, all rights reserved).