Malnutrition in critically ill patients with cirrhosis is a frequent but often overlooked complication with high prognostic relevance. The Nutrition Risk in Critically ill (NUTRIC) score and its modified variant (mNUTRIC) were established to assess the nutrition risk of intensive care unit patients. Considering the high mortality of cirrhosis in critically ill patients, this study aims to evaluate the discriminative ability of NUTRIC and mNUTRIC to predict outcome. We performed a retro-prospective evaluation in 150 Caucasian cirrhotic patients admitted to our ICU. Comparative prognostic analyses between NUTRIC and mNUTRIC were assessed in 114 patients. On ICU admission, a large proportion of 65% were classified as high NUTRIC (6–10) and 75% were categorized as high mNUTRIC (5–9). High nutritional risk was linked to disease severity and poor outcome. NUTRIC was moderately superior to mNUTRIC in prediction of 28-day mortality (area under curve 0.806 vs. 0.788) as well as 3-month mortality (area under curve 0.839 vs. 0.819). We found a significant association of NUTRIC and mNUTRIC with MELD, CHILD, renal function, interleukin 6 and albumin, but not with body mass index. NUTRIC and mNUTRIC are characterized by high prognostic accuracy in critically ill patients with cirrhosis. NUTRIC revealed a moderate advantage in prognostic ability compared to mNUTRIC.