Born in Småland, Per Bertilsson grew up in Göteborg and represented the Göteborgs GS. He then moved to Stockholm to be trained as a gymnastics teacher. In 1912, he was a member of the Swedish team that won gold in the Swedish system team event at the Stockholm Olympics. His brother Carl won gold in the same event four years earlier in London. Subsequently, Per Bertilsson worked as a fencing teacher in Cuba’s capital Havana, where his Olympic medal was stolen.
After his return, he joined the Älvsborg Regiment’s reserve as a second lieutenant in 1918. In 1921, he was promoted to lieutenant and, in 1934, to the rank of captain. He worked as a gymnastics teacher in Göteborg (Gothenburg). In 1934, he bought an old croft in village Delsjökärr east of Göteborg as a summer residence. Starting with a simple catering business, Bertilsson’s cabin became a very popular excursion destination. This was mainly due to the efforts of his wife Astrid, who took care of the family’s finances. Bertilsson himself became some kind of early conservationist. Eventually, he received the City of Gothenburg’s Medal of Merit in 1968. Bertilsson was married to Astrid Maria Victoria Engström, with whom he had two sons and one daughter. His wife was also trained as a gymnastics teacher.