[5] On 2 February 2010, it was confirmed Gytkjær would leave Lyngby when his contract expired in the summer to join Danish Cup winners Nordsjælland on a free transfer, signing a three-year contract,[6] following in the footsteps of Andreas Bjelland, Andreas Laudrup and Morten Nordstrand, who had left Lyngby for the Farum-based club.

While his future had been set, Gytkjær was still to play out the remainder of the 2009–10 season with Lyngby, where he was targeted by the supporters who disapproved in seeing another player their team had nurtured head over to neighboring rivals.

[7] Gytkjær made his debut for Nordsjælland in a 2–0 away defeat to Superliga champions Copenhagen on 14 August 2010, when he was brought into the team to replace Nicki Bille Nielsen, who was sold to Villarreal.

[14] He made his debut for the club during the 2017–18 UEFA Europa League second qualifying round away game against FK Haugesund, which Lech lost 3–2.

[17] On 19 July 2020, during his last game for Lech, he scored twice in a 4–0 home win against Jagiellonia Białystok and led the team to secure second place in the 2019–20 season.

[19] During the three years at Lech Poznań, he played in 119 games and scored 65 goals, which made him the best foreign goalscorer in club's history.

[20] On 22 July 2020, Gytkjær joined newly promoted Italian Serie B side Monza on a free transfer, signing a two-year contract with the option of a third.