Measurement, a crucial step in any quality improvement activity, is difficult in two important patient safety processes: hand hygiene and patient identification. This study describes a program at the UCLA Medical Center, called Measure to Achieve Patient Safety (MAPS), which uses undergraduate student volunteers to carry out observations in the hospital. This program has been an important part of UCLA's efforts for quality improvement in patient safety efforts. Since 2004, approximately 20 students per year plus two student leaders have been selected to participate in the MAPS program. They were trained in techniques of measuring and observation and in professional behavior. They participated in weekly and monthly meetings with program leadership, received continuing education from the UCLA patient safety staff, and were trained in observational measurement. The students' observational results have been systematically reported to clinicians and departmental and hospital leadership. Handwashing increased from 50% to 93%, and nurses' checking of two identifiers at the time of medication administration increased from 50% to 95%. Compliance with proper patient identification at the time of nurse-to-transporter handoffs of patients for procedures increased to >90%. This unique program has made a significant contribution to UCLA's quality, safety, and service programs. MAPS has been widely accepted by the clinical staff and has also been valuable to the student volunteers. Such an approach is easily adaptable to other academic medical centers.