Background: Collagen IV-related nephropathies can lead to End Stage Renal Disease. Experimental studies have shown renin angiotensin aldosterone system blockade can reduce proteinuria and preserve renal function. In humans there is no proven treatment. Methods: This is a retrospective study of patients with Collagen IV-related nephropathies and proteinuria treated with enalapril analyzing the evolution of proteinuria and renal function, as well as predictive variables of progression to end stage renal disease. Outcome was creatinine clearance < 60 ml/min/1.73m2.