Enteral nutrition through a nasogastric tube is a technique often used with hospitalized patients when they present problems with oral nutrition. Patients receiving enteral nutrition show several kinds of complications such as diarrhoea, vomiting, constipation, lung aspiration, tube dislodgement, tube clogging, hyperglycaemia and electrolytic alterations. We present a prospective and observational study carried out in an Internal Medicine Unit with 64 patients who were fed by a nasogastric tube. From the results it can be seen that older people represented a majority (the average age was 76.2 years), and difficulty in swallowing was the main reason for beginning enteral nutrition. The complications which appeared were: tube dislodgement (48.5%); electrolytic alterations (45.5%); hyperglycaemia (34.5%); diarrhoea (32.8%); constipation (29.7%); vomiting (20.4%); tube clogging (12.5%); and lung aspiration (3.1%). We discuss the possible relationship between the different factors associated with the enteral nutrition procedure and the occurrence of these complications. Finally, some nursing interventions are suggested, such as: checking the gastric residue periodically; attempting to place the tube in the duodenum in unconscious patients; and the use of protective mittens in disturbed patients.