At this point, he was drafted to forced labour service, from which he managed to escape during transportation of his company.

Biographers tell an incredible story about Rényi: after half of a year in hiding, he managed to get hold of a soldier's uniform and march his parents out of the Budapest Ghetto, where they were captive.

He did his postgraduate in Moscow and Leningrad, where he collaborated with a prominent Soviet mathematician Yuri Linnik.

After a brief assistant professorship at Budapest, he was appointed Professor Extraordinary at the University of Debrecen in 1949.

In 1950, he founded the Mathematics Research Institute of the Hungarian Academy of Sciences, now bearing his name, and directed it until his early death.

In probability theory, he is also known for his parking constants, which characterize the solution to the following problem: given a street of some length and cars of unit length parking on a random free position on the street, what is the mean density of cars when there are no more free positions?

"[13] The Alfréd Rényi Prize, awarded by the Hungarian Academy of Science, was established in his honor.