En el artículo se problematiza el Peritaje Social realizando un recorrido por sus principales aspectos configurativos, tanto conceptuales como prácticos. A su vez, aborda un nudo que se cree es central en esta materia; hablamos del vínculo entre Peritaje y Diagnóstico en Trabajo Social, entendidos y/o trabajados generalmente de manera indistinta, cuestión que se pretende desmitificar aunque sin restar valor a cada uno. Finalmente se realiza una revisión teórica a los aportes de Mary Richmond, Gordon Hamilton y Helen Perlman en materia diagnóstica, como posibilidad de régimen de mirada disciplinar en este campo.   In this article, Social Assessment is problematized carrying out a review of its main constitutive aspects, both conceptual and practical. In turn, this text deals with an argument that is believed to be essential in this subject: the link between Assessment and Diagnosis in Social Work, usually understood and/or treated indistinctly, which is intended to be demythicised whithout detracting from each one of them. Finally, a theoretical review of the contribution made by Mary Richmond, Gordon Hamilton and Helen Perlman in diagnostic issue is carried out, as a possibility of regime of a disciplinary viewpoint in this field.