The nosological concepts of ‘bouffée délirante’, first described by Magnan in the 1880s, and of ‘psychogenic psychosis’, first described by Wimmer in 1916, are still in use in their countries of origin, France and the Scandinavian countries. Both refer to psychotic episodes of good prognosis, not connected with schizophrenia, appearing in a special fragile personality. An examination of the diagnostic criteria of the two categories shows, however, that important differences exist. Contrary to what has been claimed, Wimmer’s original description, although showing an encyclopedic knowledge of the international literature of the day, has not been directly influenced by Magnan. Bouffée délirante and psychogenic psychosis, whatever their differences, have survived in their respective countries of origin against the pressure of the psychiatric consensus of the rest of the world, as evidenced by the frequency of the present use of the two diagnoses. The two categories, after having been considered for a long time as idiosyncratic peculiarities of individual national schools, are now submitted internationally to empirical studies and have become the center of a renewed interest.