Serritslev played most of his career for Vejle Boldklub in a successful period.

In 2006 Serritslev returned to his childhood club Vejle as sports manager.

[2] On 23 November 2015, he became new manager of the Papua New Guinea national football team.

[3] On 5 June 2016, he guided Papua New Guinea to the semi-finals of the OFC Nations Cup for the first time.

[4] Papua New Guinea beat Solomon Islands 2–1,[5] before losing the final to New Zealand in a penalty shoot-out.