Puerperal psychoses are traditionally considered to be nosologically unspecific. They are defined exclusively by their occurrence close to delivery. Attempts to further diagnostically subdivide puerperal psychoses have been prevented to date by the influence of Kraepelin's dichotomy. New possibilities of nosological differentiation arose out of Kasanin's (1933) description of schizoaffective psychoses and out of Leonhard's differentiated nosology (1986). The objective of the present, retrospective study was to apply Leonhard's nosology to 42 postpartal psychoses. Five diagnostic groups could be identified: 6 cases of manic-depressive disorder, 7 cases of pure depression, 8 cases of pure melancholia, 2 cases of unsystematic schizophrenia, and 19 cases of cycloid psychoses. For this reason we consider that the concept of the cycloid psychoses is appropriate for the characterization of a large proportion of childbed psychoses.