Quantitative sensory testing (QST) is increasingly used in pediatric chronic pain; however, assessment in youth with acute musculoskeletal (MSK) pain is limited. This study evaluated the feasibility, reliability, and sources of variability of a brief QST protocol in two clinical samples of youth with acute MSK pain. Participants were 277 youth (Mage=14.5 years, SD=2.0, range=11-18 years, 59% female, 83% non-Hispanic) across 3 geographic study sites who completed a QST protocol assessing pressure and thermal pain sensitivity, temporal summation of pain (TSP), and conditioned pain modulation (CPM) 8-weeks post MSK surgery (n=100) or within 4-weeks following an acute MSK injury (n=177). High feasibility was demonstrated by protocol completion rates ranging from 97.5%-100% for each task, with 95.3% of youth completing all tasks. Reliability was high, with reliability coefficients > 0.97 for 7 out of 8 QST parameters and minimal influence of examiner or participating site effects. Younger youth had lower pressure and heat pain thresholds (11-12 vs. 13-18 years, d=-0.80 to -0.56) and cold pain tolerance (d=-0.33). Hispanic youth had higher pressure and heat pain thresholds (d=0.37-0.45) and pain ratings for cold pain tolerance (d=0.54) compared to non-Hispanic youth. No significant differences were observed in QST values by sex or personal contextual factors at time of assessment (momentary pain, menstrual period, use of pain medications). Overall findings demonstrate feasibility of a brief QST protocol with youth with diverse acute MSK pain and data provide initial support for the reliability of this QST protocol for multisite research studies.