The author underlines the variability of crime in time and cultures. This makes it difficult to correlate simply organic factors and criminal behavior. Historical and classical theories in bio-medical genesis of crime are reminded, specially anthropological and typomorphological studies. Then are reviewed modern studies on hereditary factors and chromosomal abnormalities and also ethology and neurophysiology in aggressivity. The main neuropsychiatric factors are listed: mental illnesses, epilepsy, automatical behavior during sleep, alcoholism, drug addiction. Finally, the author emphasizes the multiple determinism in criminal behavior and the continuous relationship between environment and the central nervous system.