Nutritional status before and after heart transplantation was analyzed from retrospective data on 65 patients (82% male, mean age, 43.1 years, and mean length of illness before transplantation, 57.3 months). Of all the patients 93% were on a 2 gm low sodium diet, and 55% were on a low saturated fat and low cholesterol diet before surgery. After surgery 100% of patients were on the same salt-, fat-, and cholesterol-restricted diet. Visceral protein stores (determined from albumin and total lymphocyte count) and somatic protein stores (determined from weight-for-height calculations, triceps skin fold, and arm muscle circumference) increased significantly from before surgery to 6 months after surgery. The number of patients with adequate visceral protein stores increased from 66.1% to 98.1%, and those with adequate somatic protein stores increased from 67.2% to 84.6%. Weight was analyzed over time with analysis of variance. Patients gained weight (preoperative mean = 72.8 kg and postoperative mean at 6 months = 80.2 kg), and ideal body weight increased from 102% to 114%. With paired t tests the following differed before and after surgery (p less than or equal to 0.05): cholesterol levels increased from 180 to 262 mg/dl, and triglyceride concentrations increased from 139 to 221 mg/dl. In conclusion, patient protein stores returned to normal after surgery, patients increased body weight to more than 110% of ideal, and cholesterol and triglyceride levels became elevated.