Digoxin levels were measured perspectively in the serum of 12 patients subjected to cholecystectomy and in serum and bile (Kehr) of 15 patients who underwent cholecystectomy plus choledochostomy in order to assess adequate digitalization. All patients were volunteers with no cardiac problems. In the cholecystectomy group serum digoxin levels increased in all patients from the second to the fourth postoperative day (P = 0.0001), while in patients with choledochostomy both serum and bile digoxin levels displayed wide variations. This last finding was associated with signs reflecting inadequate digitalization, probably due to significant digoxin losses through the choledochostomy.