This study's purpose was to evaluate feasibility and acceptability, obtain preliminary efficacy data, and evaluate predictors of improvement with iDOVE, a technology-augmented violence and depression prevention intervention for high-risk adolescents seen in the emergency department (ED). We conducted a pilot randomized controlled trial (RCT) with 116 English-speaking adolescents (ages 13-17 years), presenting to the ED for any reason, who reported past-year physical peer violence and current depressive symptoms. The cognitive-behavioral therapy- and motivational interviewing-based intervention consisted of a brief in-ED intervention session and 8 weeks of automated text-message daily mood queries and tailored responses. The control was a brief in-ED presentation and twice-weekly text messages on healthy behaviors. Follow-up was conducted at 8 and 16 weeks. Descriptive statistics, bivariate comparisons, mixed-effects longitudinal regression models, and latent class models (LCMs) were calculated. iDOVE had high acceptability and feasibility, with 86% of eligible youth consenting (n = 116), 95% completing 8-week follow-up, and 91% completing 16-week follow-up. High quantitative and qualitative satisfaction were reported by intervention and control participants. Comparing intervention to control, improved depressive symptoms (p = .07) and physical peer violence (p = .01) were observed among the more symptomatic youth in the intervention group (but no difference in symptoms between full intervention and control groups). LCMs showed that intervention responsiveness correlated with lower mood (measured through daily text messages) at Day 7 of the intervention. This RCT of a technology-augmented intervention shows high feasibility and acceptability and a promising signal of reduced violence among the highest-risk participants. (PsycINFO Database Record (c) 2018 APA, all rights reserved).