He married Valéria Geiger (1879-1978) in December 1905. They had two sons, Gedeon Dienes (1914) and Zoltan Paul Dienes (1916). Following their divorce, he married Sari Dienes in 1922.
From 1921 to 1923 he lectured at University College, Swansea, where his students included Evan Tom Davies. From 1923 to 1948 he was Professor of Mathematics at Birkbeck College, London, where his students included Ralph Henstock and Abraham Robinson.