The Therapeutic Community for Personality Disorders at Clinica San Miguel has been functioning since March 2007 with the purpose of conducting an intensive psychotherapeutic treatment of people with severe personality disorders. In this paper we describe the theoretical basis of our model, relating both to our conception of personality pathology, and to the unit structure, the day to day functioning and the experience along these last six years. Keywords: therapeutic community, personality disorders, psychotherapy, transitional space, narcisism, self development, institution.