[The symbolic characters of the Seven Deadly Sins can be traced from time to time in the cultural history of human mankind, being directly specified in certain artistic products. Such are, among others, the painting entitled „The Seven Deadly Sins and the Four Last Things” by Hieronymus Bosch and the poems Divina Commedia and The Faerie Queene by Dante Alighieri and Edmund Spenser, respectively. However, there are several paragraphs referring to these behaviours of the Seven Deadly Sins in the Bible and in the dramas of William Shakespeare. The objective of the present review is to propose that dysfunctions in the central serotonergic system might be involved in the the neurobiology of these ’sinful’ behaviour patterns. Evidences indicate that behaviour traits such as Accidia (Sloth), Luxuria (Lust, Lechery), Superbia (Pride), Ira (Wrath, Anger), Invidia (Envy), Avaritia (Greed, Avarice), and Gula (Gluttony) can relate to the functional alterations of serotonin in the brain. Results of biochemical and molecular genetic (polymorphism) studies on the human serotonergic system (receptor, transporter, enzyme), findings of functional imaging techniques, effects of depletion (or supplementation) of the serotonin precursor tryptophan, data of challenge probe investigations directed to testing central serotonergic functions, alterations in the peripheral serotonin measures (platelet), and the changes in the CSF 5-hydroxy-indoleacetic acid content indicate such serotonergic involvement. Furthermore, results of animal experiments on behaviour change (aggressive, dominant or submissive, appetite, alcohol preference) attributed to serotonin status modification and the clinically evidenced therapeutic efficacy of pharmacological interventions, based on the modulation and perturbation of the serotonergic system (e.g. selective serotonin reuptake inhibitors), in treating the ’sinful’ behaviour forms and analogous pathological states reaching the severity of psychiatric disorders (depression, sexual disturbances, social phobia, impulsivity-aggression, obsessive-compulsive and related spectrum disorders, paranoid jealousy, eating disorders) all strongly suggest the possibility that brain serotonin dysfunctions might underlie the neurophysiology of the Seven Deadly Sins.]