UNLABELLED: This investigation determined the psychometric properties and acceptability of an animated face scale presented on a hand-held computer as a means to measure pediatric pain and mood. In study 1, 79 hospitalized, pediatric patients indicated their levels of pain by adjusting the expression of an animated cartoon face. The first objective was to determine feasibility, concurrent validity, and acceptability of the method. All patients were tested both with the Computer Face Scale and the poster format of the Wong-Baker Faces Scale. A second objective was to evaluate test-retest reliability of the method. In study 2, 50 hospitalized, pediatric patients were tested on 2 occasions, but in this case the patients used the Computer Face Scale to indicate both their pain (how much they hurt) and their mood (how they felt). Children in study 1 were able to use the Computer Face Scale to express relative amounts of pain/hurt; the method showed concurrent validity with the Wong-Baker Face Scale; and most children expressed a preference for the Computer Face Scale. The method also showed adequate test-retest reliability. In study 2, adequate test-retest reliability was demonstrated for ratings of both pain and mood. PERSPECTIVE: The Computer Face Scale allows the health provider to obtain reliable and valid measures of pediatric pain and mood. The method can be understood and used by children as young as 3 years and is appropriate for use with adults.