He played 33 times for Norway,[2] and his 26 international goals place him third on the national team's all-time scoring list.

[3] His nickname Jeja means literally "Me Then", as that was what he wondered as a kid when he was not picked for the team.

He was also a member of the Norwegian team that played in the 1920 Olympics,[4] and scored twice in the 3–1 win against England's amateur side.

In September 2024, Norway's anti-doping agency mistakenly included Gundersen and Jørgen Juve on a list of football players to be tested.

We can joke about it in the office today and then review our routines going forward.