This study aims to investigate the primary processes of thoughts and how these are expressed in the Thematic Apperception Test (TAT). The primary process, characteristic of schizophrenic individuals, is an essential concept in the psychoanalytic theories concerning the unconscious aspects of psychic functioning. It is characterized by the absence of coherence and logical relationships, unawareness of temporal relationships and the reality principle. In this study, the TAT was analyzed according to the Parisian School, focusing particularly the emergences of the primary processes. The participants were 32 individuals divided in two groups of 16 each: a clinical group medically diagnosed as schizophrenic patients and a nonclinical group with 50% men and 50% women between 24 and 60 years of age. The study considered the procedures of Series A, B, C, and E of the TAT discourse analysis sheet. The Mann-Whitney test showed statistically significant differences between the groups in the E Series. Also, nine subcriteria from the E Series correctly classified 93.8% of the sample. It has been concluded that the E Series of TAT adequately differentiates between the clinical group diagnosed with schizophrenia and the group of individuals without this pathology.