The article discusses the causes and course of the last illness of I.S. Turgenev. The writer was consulted by many famous French and Russian doctors who made various diagnoses and used various methods of treatment. The primary disease that caused Turgenev's death is myxosarcoma (one of the sarcoma variants), involving soft tissues and thoracic vertebrae. The article presents data and discusses alternative diagnostic versions about the nature of the disease and the causes of death of the great Russian writer.