After the seizure of Lviv by the Soviets, in the years 1944-1946, Tadeusz Marciniak worked in the Descriptive Anatomy Department in the State-Medical Institute of Lviv and also performed the function of the dean of the Medical Faculty. On receiving a proposal to assume the Chair of the Anatomy Department in Wrocław, he made the decision to leave Lviv. By July 2nd, 1946, prof. Tadeusz Marciniak had taken over the duties of full professor of the Descriptive Anatomy Department of the Medical Faculty of the University and the Technical College of Wrocław. On taking his job in Wrocław, prof. Marciniak undertook attempts to restore the worn out parts of the Anatomy Department building. Due to the lack of Polish manuals, he also took to the preparation of scripts for medical students. Professor Marciniak was a member of the Wrocław Section of the Polish Anthropological Association and a regular member of the Wroclaw Association of Science. His main scientific interests referred to the morphogenesis of the central nervous system and urinary system. He concentrated on circulatory system and muscular system tetralogies. Professor Marciniak also actively participated in administrative work at the university. In the years 1947-1948, he held the office of associate dean of the Medical Faculty, and till 1950 was a member of the Senate of the University and Technical College of Wrocław. In the years 1959-1962, he was a vice rector of the Medical University of Wrocław.