Issues of alcohol and drug use are more pronounced during adolescence than at any other period of the lifespan and represent a significant public health concern in the United States. As a result, there is currently a need for research on developmentally appropriate interventions for adolescent substance use (SU). Nurses and other mental health professionals working with adolescents need effective evidenced-based programs to refer clients having issues with SU. The current pilot study evaluated the effectiveness of the Youth Alternative Solutions Program, a hospital-based intervention program at a Level I trauma center in Southern California that partners with community stakeholders to accomplish its goals. A sample of 27 adolescents was recruited from August 2010 until October 2011. Twenty-seven total participants completed both pretest and posttest questionnaires; 14 of these participants also completed follow-up data collection. Results indicated a significant increase in negative alcohol outcome expectancies between the three study time points. More comprehensive studies of the Youth Alternative Solutions Program should be conducted in the future to determine the utility of hospital-based SU interventions and to provide evidence of the program’s long-term effects.