The conflict between French nosology and international classifications is mainly linked to the French concepts of chronic hallucinatory psychosis and bouffée délirante. However, these discrepancies are now largely reduced by the evolution of the recent versions of international classifications. The term chronic hallucinatory psychosis is used to describe a chronic hallucinatory and delusional disorder that differs from paranoid schizophrenia in the absence of formal thought disorder and intellectual impairment. This concept appears to be quite similar to paranoid schizophrenia as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM) and International Classification of Disease (ICD). However, the recent statement that deficit and nondeficit schizophrenia are separate diseases rediscovered French distinctions between chronic hallucinatory psychosis and schizophrenia. The term bouffée délirante describes an acute nonaffective and nonschizophrenic psychotic disorder, which is largely similar to DSM-III-R and DSM-IV brief psychotic and schizophreniform disorders, and was taken up in ICD-10 under the name acute polymorphic psychotic disorder.