Adolescent day programs (ADPs) have treatment outcomes as good as, or better than, regular outpatient treatment for adolescents who present with emotional, behavioral, social, and psychiatric disorders. However, they may be more costly, and the mechanisms of change within them are unknown. Identification of the most important curative factors could enable the streamlining of these programs. This descriptive study examined the perceptions of curative factors in ADP treatment as rated by 38 participants, 51 of their parents, and 14 clinicians. Findings were variable across informant groups. Adolescent respondents reported Universality, Acceptance, Learning from Interpersonal Action, Decision Making, Altruism, Guidance, and Instillation of Hope to be equally the most helpful curative factors in the program. Clinicians ranked Acceptance to be the most important factor, followed by Decision Making, Self-Understanding, Vicarious Learning, and Universality. Parents ranked Acceptance, Universality, Guidance, and Instillation of Hope as being most helpful. The findings provide directions for the enhancement of ADPs.