The aim of the study was to define the features, prevalence, and pathophysiology of therapy for muscle cramps in cirrhotic patients. The first protocol study included 294 cirrhotic patients and 194 age- and sex-matched controls. Controls were defined as inpatients or outpatients without any clinical and laboratory evidence of liver disease. Features and prevalence of muscle cramps were defined on the basis of a standard questionnaire. As far as the pathophysiological associations of muscle cramps were concerned, the following parameters were evaluated: mean arterial pressure (MAP), nutritional status, liver function tests, plasma volume (PV), plasma renin activity (PRA), and electrolyte, mineral, and acid-base status. The prevalence of cramps was higher in cirrhotic patients than in controls, and it was related to the duration of recognized cirrhosis and to the severity of liver function impairment. At a multiple regression analysis, the presence of ascites, low values of MAP, and high values of PRA were the independent predictive factors for the occurrence of cramps in cirrhosis. In the second protocol study, the effects of a sustained expansion of the effective circulating volume induced by intravenous infusion of human albumin were compared with those of a placebo in 12 cirrhotic patients with more than three cramp crises a week. Compared with the placebo, albumin reduced the cramp frequency (P < .01). In conclusion, an increased prevalence of true muscle cramps occurs in patients with cirrhosis. Our data indicate that the pathophysiological link between cirrhosis and cramps may be represented by the reduction of the effective circulating volume. They also indicate that weekly infusion of human albumin may be an effective treatment for cramps in cirrhosis.