Prof. Jaroslav Polák studied in 1961 Solid state physics in Masaryk University in Brno. After study stay in the Institute of Solid State Physics in Prague he joined the present Institute of Physics of Materials. His early interests were point defects in metals. After the doctorate in 1965 he paid his attention to fatigue of materials, namely basic fatigue mechanisms. In 1970-71 he was postdoctorate fellow in the National Research Council of Canada with dr. Z. S. Basinski. He continued his work in Low cycle fatigue group in IPM as a head of the group. In 1990 he was invited by Prof. Murakami for two months stay as a fellow of Japan Society for Promotion of Science. In the period 1991 - 2002 he served as “professeur invité” in Ecole Centrale de Lille. He was awarded honorary title dr. h. c. from Ecole Centrale de Lille. He published more than 450 original contributions in international journals and conference proceedings, is co-author and editor of several volumes. In 1991 he published with Elsevier a monograph „Cyclic Plasticity and Low Cycle Fatigue Life of Metals” and contributed by two review chapters to the 4th Volume of “Comprehensive Structural Integrity”. His H index is 34. He studies basic fatigue mechanisms, namely fatigue crack initiation, short crack growth, cyclic plastic response and fatigue damage, recently in stainless steels and nickel-based superalloys. He organized the XVI. Colloquium on Mechanical Fatigue in Metals in Brno.