The effect of ethanol feeding on renal function, gross and microscopic morphology, and constituent content was determined in alcohol-fed rats and compared to similar studies in isocalorically fed animals ingesting the same diet except that dextrimaltose was isocalorically substituted for ethanol. Alcohol-fed animals have significantly reduced renal function and interstitial edema compared to their isocaloric controls. When renal mass and renal constituent analysis were normalized for body weight, alcohol-fed animals were found to have renal hypertrophy characterized by significantly increased absolute amounts of protein (p less than 0.01), fat (p less than 0.01), and water (p less than 0.01). All of these constituents increased in proportion to their percentage of total renal mass in control animals. In contrast, DNA content per kidney was similar for alcohol and isocalorically fed animals.