The paper presents the possibilities of art collecting as an art therapy. Combining the autoethnographic methodology with that of the case study, from a participant observation, it describes the reasons that led to the constitution of the Pablo de Castro Collection and the subjective process through which it has become a crucial element in overcoming and coexisting with the trauma that the confirmation of the diagnosis of Rett syndrome for his daughter entailed. A brief presentation of the relationship among collecting, art therapy and autism gives way to the explanation of the process of building the collection. Then, the turning point is identified, which made it possible to provide it with a different line from the one initially planned and which is, precisely, the one that allows the application of art therapy as the leitmotiv of its development. After an approach to Rett syndrome, the text delves into the healing concept of the act of collecting and the re-signification of the works as a strategy for establishing links that favour the repair of grief, while new realities are constructed from them - habitat, play, education - through a process of artistic meta-creation.