In round 8, Nightingale made his NRL debut for the St George Illawarra Dragons against the Penrith Panthers, playing on the wing and scoring a try on debut in the 28-16 win at Jubilee Oval. He finished his debut season with 7 tries from 16 matches.
2008
Nightingale was selected for New Zealand for the 2008 Centenary Test against Australia, making his international debut for New Zealand on the wing in the Kiwis 28-12 loss at the SCG. Nightingale finished the 2008 NRL season playing in 24 matches and scoring 13 tries for the Dragons. In August 2008, Nightingale was chosen for the New Zealand training squad for the 2008 Rugby League World Cup. Nightingale originally missed out of the final 24-man Kiwis squad for the World Cup, but was chosen as a replacement for the injured Brent Webb. Nightingale only played in 1 match in the World Cup, playing against England and scored a try in the Kiwis 36-24 win at Hunter Stadium.
2009
In 2009, Nightingale was selected for St George Illawarra's feeder side Shellharbour Dragons for some matches during the season after being stuck behind Brett Morris and Wendell Sailor on the wing. Nightingale was selected on the interchange bench for the Kiwis 2008 Anzac Test in the 38-10 loss against Australia at Suncorp Stadium. Nightingale played in 18 matches and scored 3 tries for the Dragons in the 2009 NRL season.
2010
In 2010, after the retirement of Wendell Sailor, Nightingale returned to the starting lineup on the wing. For the 2010 Anzac Test, Nightingale was selected to play for New Zealand on the wing, scoring a try in their 12-8 loss against Australia at AAMI Park. On 3 October 2010, in the Dragons 2010 NRL Grand Final against the Sydney Roosters, Nightingale played on the wing and scored two second-half tries to help the Dragons to achieve the 32-8 victory. Nightingale played in 26 matches and scored 16 tries in the Dragons successful 2010 NRL season. Nightingale was chosen in the New Zealand Kiwis2010 Rugby League Four Nations squad, scoring three tries in four games, including a 71st minute try in the final at Suncorp Stadium. Nightingale's fine late season form saw him earning a place in Rugby League World's team of the year on the wing.
2011
On 9 March 2011, Nightingale extended his contract with the Dragons for a further 4 years until the end of the 2015 season. Nightingale was selected for the Kiwis for the 2011 Anzac Test against Australia on the wing in the Kiwis 20-10 loss at Cbus Super Stadium. In round 19, against the Cronulla-Sutherland Sharks, Nightingale played his 100th National Rugby League career match in the Dragons 38-8 win at Jubilee Oval. Nightingale was named the Dragons ‘Player of the Year’ for the 2011 NRL season, playing in 25 matches and scoring 10 tries for the Dragons. Nightingale was selected for the New Zealand national rugby league team 2011 Rugby League Four Nations squad, playing in 4 matches and scoring 3 tries.
2012
On 4 February 2012, Nightingale was selected for the NRL All Stars team against the Indigenous All Stars playing on the wing in the 36-28 win at Cbus Super Stadium. Nightingale was selected for the Kiwis for the 2012 Anzac Test against Australia on the wing in the Kiwis 20-12 loss at Eden Park. Nightingale played in all of the Dragons 24 matches and scored 7 tries in the 2012 NRL season.
2013
Nightingale was selected for the Kiwis for the 2013 Anzac Test against Australia on the wing in the Kiwis 32-12 loss at Canberra Stadium. In round 20, against the Canberra Raiders, Nightingale played his 150th NRL career match in the Dragons 22-18 loss at Canberra Stadium. Nightingale played in all of the Dragons 24 matches and scored 9 tries in the 2013 NRL season. Nightingale played for the Kiwis in the 2013 Rugby League World Cup. Nightingale was selected in the New Zealand 2013 World Cup squad, playing in 2 matches.
2014
In February 2014, Nightingale was selected for the St George Illawarra Dragons inaugural 2014 Auckland Nines squad. On 2 May 2014, Nightingale was selected for the Kiwis for the Anzac test against Australia on the wing in the Kiwis 30-18 loss at the SFS. Nightingale finished off the 2014 NRL season as the Dragons highest tryscorer with 16 tries in 22 matches. On 7 October 2014, Nightingale was selected in the New Zealand Kiwis final 24-man squad for the 2014 Four Nations series. Nightingale played on the wing and scored a try in the Kiwis 22-18 Four Nations final win over Australia at Westpac Stadium. Nightingale finished as the tournament's top try scorer with 5 tries after 4 games.
2015
On 21 January 2015, Nightingale was named in the Dragons 2015 NRL Auckland Nines squad. On 3 May 2015, Nightingale was selected for the Kiwis for the 2015 Anzac Test against Australia on the wing in the Kiwis 26-12 win at Suncorp Stadium. On 19 June 2015, Nightingale re-signed with the Dragons on a 2-year contract until the end of the 2017 season after attracting offers from the New Zealand Warriors and the Cronulla-Sutherland Sharks. Nightingale finished the 2015 NRL season playing in 17 matches and scoring 5 tries for the Dragons. On 8 October 2015, Nightingale was selected in the 23-man New Zealand squad to tour England. Nightingale played in all 3 matches against England on the wing and scored a try in the Kiwis' 2-1 Baskerville Shield series loss.
2016
In round 3, against the South Sydney Rabbitohs, Nightingale played his 200th NRL career match, scoring a try in the Dragons 8-6 win at the Sydney Cricket Ground. On 6 May 2016, Nightingale played for the New Zealand Kiwis against Australia, playing on the wing in the 16-0 loss at Hunter Stadium.
2017
Nightingale was one of 5 players to have played all 24 games for the St. George Illawarra Dragons in 2017 and for the third season, was the club's top tryscorer. Overall, Nightingale finished equal sixth for tries scored in the 2017 NRL season. In Round 16 vs Newcastle Knights, Nightingale scored his 100th try in a winning effort of 32-28 in a second-half comeback.
2018
On 9 August 2018 it was reported that Nightingale had announced his retirement from rugby league, effective at the end of 2018.
