Freud considers that angst is a phenomenon of the greatest importance in clinic, and the main problem of neurosis, since the most diverse and meaningful problems converge in it. Throughout his work, angst is the motif of important, although complex, elaborations, which can be distributed among two periods: 1894-1918 and 1926- 1939. Those of the second period carry the mark of three theoretical axes: the second pulsional dualism (life pulsion/death pulsion); the second scheme of the psychic’ apparatus (Ego, Id, and Superego); and the last findings on children sexuality.