Frances Tustin was a renowned child therapist that, with her original conceptions and therapeutic effectiveness, stemming mainly from the clinical work with autistic and psychotic children, expanded the existing theories on the primitive states of mind influencing therapists in their clinical and academic work and acquiring a broad spectrum of activity. This study aimed to trace the course of the theoretical work of Frances Tustin in the original language in which it was produced. To this end, it was used a historical approach, to investigate the origins of a thought and its various contextual determinants as the biography of the author, the historical period, clinical cases, among others. The research material was the complete writings of Frances Tustin. From a detailed review process the work was divided into three main periods:

1. 1) Early Writings;

2. 2) Elaborations and

3. 3) Revisions.

Her theoretical corpus has not only assisted the attendance of atypical children, but also psychotic, borderline and neurotic adult patients. It enabled contact and exchange experiences with workers from various institutions elucidating the affective aspects involved in the functioning of patients and the dynamics of their relationships with caregivers. Her theoretical and technical contributions are widely known and respected in many countries. It remains modern among the significant neuroscience advances as a complementary contribution for a greater understanding on the psychodynamics of the most regressed states of mind.