Background: No prognostic tools are established for alcohol-related liver disease (ALD). Collagen proportionate area (CPA) measurement is a technique that quantifies fibrous tissue in liver biopsies using digital image analysis. Aim: To assess the predictive value of CPA on hepatic decompensation and liver-related mortality in ALD. Methods: In a multicentre cohort study, we included 386 patients with biopsy-verified ALD and with long-term follow-up. In the development cohort of 276 patients, we assessed the predictors of hepatic decompensation and liver-related death in standard and competing risk multivariable Cox regression analyses. The results were validated in an independent prospective cohort of 110 patients, where CPA was also correlated with liver stiffness measurement (LSM). Results: In the development cohort, 231 (84%) patients had early/compensated ALD (non-cirrhotic or compensated cirrhosis) and 45 (16%) had decompensated cirrhosis. In the validation cohort, all patients had early/compensated ALD. Independent predictors of liver-related mortality were higher CPA values (HR = 1.04, 95% CI 1.02-1.04) and advanced fibrosis (HR = 2.80, 95% CI 1.29-6.05) with similar results in standard and competing risk multivariable Cox regression analysis. In early/compensated ALD, CPA was the only independent predictor of hepatic decompensation and liver-related death (HR = 1.08, 95% CI 1.06-1.11). In the prospective cohort, we validated that CPA independently predicts hepatic decompensation in early/compensated ALD. The predictive power of CPA and LSM was equally strong. Conclusions: CPA predicts liver-related mortality in ALD and hepatic decompensation and/or liver-related death in early/compensated ALD. Traditional histological assessment may benefit from the addition of CPA to the evaluation of ALD.