Resumen: The goal of our study was to understand the characteristics of non-attenders to a first appointment in a mental health center in order to improve the response to the referral. Various characteristics (sex, age, rural or urban provenance, origin of derivation, days on waiting list, destination of derivation, and principal diagnosis) of the patients attended by the service during one year (N = 433) were evaluated and compared with those of the non-attenders during the same period of time (N = 95). First attenders to the mental health service spent less days on the waiting list than non-attenders, and were mostly derived from emergency services. We conclude that first non-attenders unnecessarily enlarge the unit''s waiting list, a fact which paradoxically relates to non-attendance of these same patients. The use of several ways to improve the nonattendance rates is discussed. Idioma: Español DOI: 10.5944/rppc.vol.19.num.2.2014.13064 Año: 2014 Publicado en: Revista de psicopatología y psicología clínica 19, 2 (2014), 141-146 ISSN: 1136-5420 Tipo y forma: Artículo (Versión definitiva) Área (Departamento): Área Psicología Social (Dpto. Psicología y Sociología) Área (Departamento): Área Psicolog.Evolut.Educac (Dpto. Psicología y Sociología) Área (Departamento): Área Métod.Invest.Diag.Educac. (Dpto. Ciencias de la Educación) Área (Departamento): Área Person.Eval.Trat.Psicoló. (Dpto. Psicología y Sociología)