* ActorAllusion:
** Danno, responding to an offer of whiskey from a helicopter pilot played by Music/JimmyBuffett: "I'm more of a margarita guy myself."
** Undercover, dressed up as players at an illegal casino, Danno asks Steve, "How come I look like a waiter and you look like Film/JamesBond?" Alex O'Loughlin was considered for James Bond before losing out on the part to Daniel Craig while Scott Caan has been put into a waiter's uniform more often than not in Film/OceansEleven and the sequels.
** [[Creator/MasiOka Max]] begins an episode talking about the plausibility of time-travel. In another episode, he asks an ICE agent (played by Greg Grunberg) if they've met before. Both were on ''Series/{{Heroes}}''.
** Danno, played by Scott Caan, refers to a suspect, played by his father James Caan, as "old man."
** In one episode, Steve opens a fridge to find it filled with bottles of blood. Danny jokes that it is for [[Series/{{Moonlight}} vampires]].
** [[Series/{{Lost}} John Locke]] is pals with [[Series/{{Lost}} Jin]] again.
** Creator/PeterWeller guest stars in the episode "[[Recap/HawaiiFive0S03E15 Hookman]]" as a sniper with [[Franchise/RoboCop prosthetic hands]].
** When Creator/DanteBasco plays a criminal, his WeaponOfChoice is a flamethrower. He provided the voice of two [[WesternAnimation/AvatarTheLastAirbender fire]][[WesternAnimation/TheLegendOfKorra benders]].
** Meeting a cop from San Francisco, Jerry remarks "more than one person escaped from Alcatraz," which is funnier considering Jorge Garcia's role on the ''Series/{{Alcatraz}}'' show.
** Aunt Deb spent the majority of her life in Los Angeles and is a talented singer, just like her actress, Creator/CarolBurnett.
* ActorSharedBackground: Lou Grover grew up in Chicago, as did his actor Chi [=McBride=].
* {{Defictionalization}}: A throwaway reference to "Kukui High School" in the pilot has led to fans [[http://www.hawaiinewsnow.com/Global/story.asp?S=13227331 creating]] a whole [[http://www.staradvertiser.com/columnists/20100926_five_0_artistic_license_spurs_offshoots_online.html backstory]] for an otherwise fictional school, complete with [[http://www.kukuihigh.com/logo-shop/ logo wear.]] In Hawaii, high schools are a big deal.
* FakeAmerican:
** Alex O'Loughlin. When in character as Steve [=McGarrett=], he sounds just like an American; when out of character (such as when being interviewed or doing promotional appearances) his Australian accent is unmistakable. Yet again, Steve's American accent is almost too pretty to be real.
** Also, Korean-Canadian Grace Park as Kono. But do know that Grace also has American citizenship, since the Canadian government does allow dual citizenship. So it may not be totally true.
** Tony Curran as a Boston-born Irish mob hitman in "Ike Maka".
* FakeBrit: Australian actress Clare van der Boom as Danny's British-born ex-wife Rachel.
* PlayingAgainstType: [[Series/{{Glee}} Coach Tanaka]] as a Filipino terrorist.
* RealLifeRelative:
** Creator/JamesCaan (father of Scott) guest starred in "Lekio" as a former cop/murder suspect.
** Daniel Baldwin plays Paul Delaney in season 3, brother of Frank Delaney played by William Baldwin.
* WhatCouldHaveBeen: Reportedly James [=McArthur=] (the original show's Danny) was set to play Danny's father in the remake when he unexpectedly died. The role was actually Mamo Kahike, which was eventually played by Al Harrington (making him the first regular from the original show to appear).
* WrittenInInfirmity: Daniel Dae Kim and Grace Park are not scheduled to appear in the 8th season due to failed negotiations over being paid less than Scott Caan and Alex O' Loughlin. The production team said that due to this, the season will explain what they are doing when it airs in 2017.
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