Following the departure of his predecessor, Vince Russo, in October 1999, Kreski became the head writer of the World Wrestling Federation. He is widely credited with writing captivating and layered storylines, and was at the helm of WWF creative in its all-time peak years of both ratings and profitability. Kreski's extensive use of storyboards was mocked by many in the WWF during his tenure, but they enabled him to achieve a high degree of continuity in his storylines, which began to devolve into semi-coherence following his departure.
Kreski was replaced as head writer by Stephanie McMahon in November 2000, but remained with the company until 2002, when he left to pursue other opportunities.