Psychic disturbances in the post-partum period are divided into the postpartum blues, postpartum depression, and postpartum psychoses. The latter are severe endogenous psychoses which mostly fulfill the diagnostic criteria for cycloid psychoses according to Leonhard. Based on three case reports, characteristic symptoms, the phasic clinical course with remissions, and distinct etiological, therapeutic, and forensic aspects of cycloid psychoses in the post-partum period are discussed. The high relapse rate of approximately 50% in patients at risk requires intensive psychiatric care in the peripartal period. In particular, the possibility of a prophylactic treatment of patients at risk with lithium immediately after delivery is emphasized. However, this sophisticated therapeutic strategy requires close cooperation between gynecologists and psychiatrists.