Background and objectives: This study had the purpose of studying gastric emptying in patients with chronic renal failure. Material and method: Thirty patients with chronic renal failure were studied, 16 in conservative clinical treatment and 14 in hemodialysis for over six months. The control group (CTL) was composed of 18 asymptomatic volunteers. The method of gastric emptying study was scintigraphy. The standardized test meal was an omelet of three chicken eggs prepared with colloidal sulfur marked with 185 MBq of 99m technetium. Gastric retention curves were studied and T of gastric emptying was obtained from them. A T value corresponding to the average of T values of control group plus twice standard deviation was considered nornmal. Statistical tests used were χ2 and Kruskal-Wallis. Results: There was no statistically significant difference with regard to total gastric retention curves and T of gastric emptying, which was similar in three studied groups. Nine patients had high T of gastric emptying, above 125 minutes. These patients were equally distributed among both genders and conservative clinical treatment and hemodialysis groups. Conclusions: We concluded that gastric retention rate and T of gastric emptying in patients with chronic renal failure in conservative clinical treatment and hemodialysis does not differ from the healthy patients group. Hemodialysis does not seem to reduce the risk of gastric retention in patients with chronic renal failure. © 2012 Elsevier Editora Ltda.6213947Goldstein, H., Murphy, D., Sokol, A., Gastric acid secretion in patients undergoing chronic dialysis (1967) Arch Intern Med, 120, pp. 645-653Brown-Cartwright, D., Smith, H.J., Feldman, M., Gastric emptying of an indigestible solid in patients with end-stage renal disease on continuous ambulatory peritoneal dialysis (1988) Gastroenterology, 95, pp. 49-51Strid, H., Simrén, M., Stotzer, P.O., Delay in gastric emptying in patients with chronic renal failure (2004) Scand J Gastroenterol, 39, pp. 516-520Dimitrascu, D.L., Barnet, J., Kirschner, T., Astral emptying of semisolid meal measured by real-time ultrasonography in chronic renal failure (1995) Dig Dis Sci, 40, pp. 636-644Ravelli, A.M., Gastrointestinal function in chronic renal failure (1995) Pediatr Nephrol, 9, pp. 756-762Dimitrascu, D.L., Barnet, J., Kirchner, T., Delayed gastric emptying in non-diabetic chronic renal failure (CRF): evidence of «uremic gastroparesis » (1993) Gastroenterology, 104 (4), pp. A500. , part 2Margolis, D.M., Saylor, J.L., Geisse, D., Upper gastrointestinal disease in chronic renal failure: a prospective evaluation (1978) Arch Inter Med, 138, pp. 1214-1217Kallar, S.K., Everett, L.L., Potencial risks and preventive measures for pulmonary aspiration: new concepts in preoperative measures for pulmonary aspiration: new concepts in preoperative fasting guidelines (1993) Anesth. Analg., 77, pp. 171-182Hadjiyannakis, E.J., Evans, D.B., Smellie, W.A.B., Gastrointestinal complication following renal transplantation (1971) Lancet, 2, pp. 781-785Vantrappen, G., Methods to study gastric emptying (1994) Dig Dis Sci, 39 (SUPPL.), pp. 91S-94SLorena, S.L.S., Tinois, E., Hirata, E.S., Estudo do esvaziamento gástrico e da distribuição intragástrica de uma dieta sólida através da cintilografia: diferença entre sexos (2000) Arq Gastroenterol, 37 (2), pp. 102-106Knight, L.C., Parkman, H.P., Brown, K.L., Delayed gastric emptying and decreased antral contractility in normal premenopausal women compared with men (1997) Am J Gastroenterol, 92, pp. 968-975Kumar, D., In vitro inhibitory effect of progesterone on extrauterine human smooth muscle (1962) Am J Obstet Gynecol, 84, pp. 1300-1304Hutson, W.R., Roehrkasse, R.L., Wald, A., Influence of gender and menopause on gastric emptying and motility (1989) Gastroenterology, 96, pp. 11-17Kao, C.H., Lai, T.L., Wang, S.J., Influence of age on gastric emptying in healthy chinese (1994) Clin Nucl Med, 19, pp. 401-404Urbain, J.L.C., Vekemans, M.C., Bouillon, R., Characterization of gastric antral motility disturbances in diabetes using a scintigraphic technique (1993) J Nucl Med, 4, pp. 578-581Kong, M.F., Horowitz, M., Diabetic gastroparesis (2005) Diabet Med, 22, pp. 3-18Minami, H., McCallum, R.W., The physiology and pathophysiology of gastric emptying in humans (1984) Gastroenterology, 86, pp. 1592-1610Urbain, J.L.C., Charkes, N.D., Recent advances in gastric emptying scintigraphy (1995) Seminars Nucl Med, 25, pp. 318-325Fried, M., Methods to study gastric emptying (1994) Dig Dis Sci, 39 (SUPPL.), pp. 114S-115SMilito, G., Taccone-Gallucci, M., Brancaleone, C., Assessment of the upper gastrointestinal tract in hemodialisys patients awaiting renal transplantation (1983) Am J Gastroenterol, 78, pp. 328-331de Schoenmakere, G., Vanholder, R., Rottey, S., Relationship between gastric emptying and clinical and biochemical factors in chronic haemodialysis patients (2001) Nephrol Dial Transplant, 16, pp. 1850-1855Adachi, H., Kamiya, T., Hirako, M., Improvement of gastric motility by hemodialysis in patients with chronic renal failure (2007) J Smooth Muscle Res, 43, pp. 179-189Kao, C.H., Hsu, Y., Wang, S.J., Delayed gastric emptying and Helicobacter pylori infection in patients with chronic renal failure (1995) Eur J Nucl Med, 22, pp. 1282-1291