 In 1965 Stefan Ślopek was elected a corresponding member of the Polish Academy of Sciences (PAN) and in 1973 as its full member.Stefan Ślopek was an outstanding specialist in the field of clinical microbiology and immunology.Motivated by his great interest in the above-mentioned subjects, as early as before the Second World War, he started working for a branch of the State Department of Hygiene in Lvov and at the same time, under a scientific guidance of Prof. N. Gasiorowski, at the Department of Clinical Microbiology of Jan Kazimierz University in Lvov.