Localized proton magnetic resonance spectroscopy (MRS) with short echo times provides unique information of human cerebral metabolism. Studies on patients with portal-systemic encephalopathy (PSE) have been performed to clarify the pathogenesis of this disease and to find a method which allows an objective diagnosis. Spectra of patients with PSE show typical abnormalities. Regional variations of these spectral changes are observed. The metabolic changes correlate with the grade of encephalopathy but the dependence on the Child-Pugh score is controversial. No causal dependence between MRS findings and abnormalities in magnetic resonance imaging is evident. Differences in magnetic resonance spectra in patients compared to controls vanish after liver transplantation, but increase after TIPS. The results of proton magnetic resonance spectroscopy are important for an understanding of the pathogenesis of PSE, but do not aid in the diagnosis of subclinical hepatic encephalopathy.