Uremic encephalopathy (UE) is a clinical syndrome, closely linked to the progression of renal failure. Many approaches can be utilized to diagnose it: EEG changes, somatosensory evoked potentials, choice reaction time test, cerebrospinal fluid (CSF) studies, brain computerized tomography, plasma and CSF amino acid concentration. On the basis of the data available at present, it is possible to postulate that UE could be caused by amino acid derangements (mainly glutamine, glycine, aromatic and branched-chain amino acids) and by the subsequent imbalance of neurotransmitters (mainly GABA, dopamine, serotonin). Disturbances of mental, neurologic, motor and hormonal functions could derive.