His scientific activity was devoted to the study of diseases of the stomach, intestines and liver;
Professor Nikolai Starostenko established, in Moldova, the School of Internal Medicine, including in the field of gastroenterology;
He published about 117 scientific papers, including seven monographs dedicated to the pathology of the digestive organs;
28 PhD theses and 4 Doctor Habilitated dissertations in medical sciences, dedicated to pathologies of the digestive tract, were defended under his direction;
Scientific research focused on the pathology of the digestive organs and the cardiovascular system, the biopotentials of internal organs in a normal state and in various pathologies, etc.;
Most scientific results were implemented in medical practice, including electric shock, applied for the first time in the Republic of Moldova in the treatment of supraventricular and ventricular tachyarrhythmias.