The author argues that the ubiquity of phantasies at various levels of mental functioning is undisputed in the current schools of psychoanalytic thought; however, she demonstrates some variations in their understanding of how the psychotherapeutic access to different configurations occurs. In the process of examining and acknowledging the central role played by unconscious phantasies in his patients’ symptoms, Freud gradually broadened the vernacular meaning of the German word ‘Phantasie’ that refers to imagination and the world of imagination, conferring on it the specific features that came to characterize its use in the psychoanalytic vocabulary. Later, the expansion of the concept derived from Melanie Klein’s clinical material obtained from child analyses gave rise to important debates. The author discusses the main points of disagreement that led to these debates, as well as their various theoretical and technical implications. Psychoanalytic associations in Latin America were strongly influenced by Klein and her followers. Thus, most of their scientific writings use the concept of unconscious phantasy put forward by the Kleinian school. Taking Kleinian principles as their starting point, Baranger and Baranger made the most original Latin American contribution to the concept of unconscious phantasy with their works on the unconscious phantasies generated by the analytic pair.