Rapid skeletal muscle loss adversely affects the clinical outcomes of liver cirrhosis. However, the relationships between the annual changes in skeletal muscle area (ΔSMA/year) and the etiology of cirrhosis, factors associated with muscle loss, and risk of mortality remains unclear. A total of 384 patients who underwent multiple computed tomography (CT) scans between March 2004 and June 2021 were enrolled in this study (median age, 67years; 64% men; median model for end-stage liver disease score, 9). Body composition and ΔSMA/year were estimated using a 3D image analysis system and data from at least two distinct CT scans. Differences in ΔSMA/year among different etiologies of cirrhosis, factors associated with rapid muscle loss (defined as ΔSMA/year ≤ - 3.1%), and the association between ΔSMA/year and mortality were examined. Patients with alcohol-associated liver disease (ALD) cirrhosis experienced more rapid muscle loss (ΔSMA/year, - 5.7%) than those with hepatitis B (ΔSMA/year, - 2.8%) and hepatitis C cirrhosis (ΔSMA/year, - 3.1%). ALD cirrhosis was independently associated with ΔSMA/year ≤ - 3.1% after adjusting for age, sex, and liver functional reserve. Over a median follow-up period of 3.8years, ALD cirrhosis, ΔSMA/year ≤ - 3.1%, and low subcutaneous adipose tissue level were found to be significantly associated with reduced survival. ALD cirrhosis (hazard ratio [HR], 2.43; 95% confidence interval [CI] 1.12-5.28) and ΔSMA/year ≤ - 3.1% (HR, 3.68; 95% CI 2.46-5.52) were also predictive of mortality. These results suggest that ALD cirrhosis increases the risk of rapid muscle loss and mortality in affected patients.