- Country: Hong Kong
- Genres: Action, Crime, Drama
- Release: 2002-12-12 (Hong kong), 2003-09-05 (China), 2016-03-17 (South Korea)
- Director: Andrew Lau , Alan Mak
- Writers: Felix Chong Man-Keung
- Language: Cantonese | English | Thai
- Stars: Andy Lau , Tony Chiu Wai Leung , Anthony Wong , Eric Tsang
- Runtime: 101 min
- Awards: 24 wins & 26 nominations
- AKA: Conflitos Internos (Brazil) , Szigorúan piszkos ügyek (Hungary) , Infernal Affairs (Indonesia) , Infernal Affairs (United States of America) , Пъклени дела (Bulgaria) , Infernal Affairs , Mou gaan dou (Hong Kong) , Põrgulik amet (Estonia) , Infernal Affairs (Finland) , Infernal Affairs - Die achte Hölle (Germany) , Mou Gaan Dou (Singapore) , Juego sucio (Spain) , Pakleni poslovi (Croatia) , Infernal Affairs (Germany) , Non-Stop Way (Hong Kong) , Infernal Affairs: Piekielna gra (Poland) , Mou gaan dou , Подвійна рокіровка (Ukraine) , インファナル・アフェア (Japan) , Kirli İşler (Turkey) , Mou Gaan Dou (India) , Infernal Affairs - Infiltrados , Notranje vražje zadeve (Slovenia) , Infernal Affairs (Thailand) , Infernal Affairs (United Kingdom) , Asuntos infernales (Argentina) , Infernal Affairs (Canada) , Σατανικές υποθέσεις (Greece) , Wu jian dao (Hong Kong) , Afaceri infernale (Romania) , 無間道 (Hong Kong) , Mou Gaan Dou (Canada) , Affaires internes (Canada) , A'mal-e sheytani (Iran) , Volavka (Slovakia (Slovak Republic)) , Infernal Affairs (Sweden) , 無間道 (Taiwan) , 无间道 (China) , Punë të skëterrshme (Albania) , Infernal Affairs (Denmark) , Infanaru Afea (Japan) , Infernal Affairs (Norway) , Dviguba rokiruotė (Lithuania) , Infernal Affairs (France, French Republic) , Infernal Affairs (India) , Infernal Affairs (Australia) , Mou gaan dou (Korea) , O anthropos tou nomou (Greece) , Mou gaan dou (Netherlands the) , Infernal Affairs - Infiltrados (Portugal, Portuguese Republic) , Pakleni poslovi (Serbia) , Satanikes ypotheseis (Greece) , Infernal Affairs (Italy) , Vô Gian Đạo (Vietnam) , Volavka (Czech Republic) , Двойная рокировка (Russian Federation) , Sho'un jahanamiah (Egypt)Mou gaan dou, 无间道, 無間道
- Plot: Chan Wing Yan, a young police officer, has been sent undercover as a mole in the local mafia. Lau Kin Ming, a young mafia member, infiltrates the police force. Years later, their older counterparts, Chen Wing Yan and Inspector Lau Kin Ming, respectively, race against time to expose the mole within their midst.
- IMDB:tt0338564
Infernal Affairs Cast · · · ALL
Andrew Lau
Director
Alan Mak
Director
Andy Lau
Lau Kin-Ming
Tony Chiu Wai Leung
Chan Wing-Yan
Anthony Wong
Wong Chi-Shing
Eric Tsang
Hon Sam
Kelly Chen
Lee Sum-Yee
Sammi Cheng
Mary
Edison Chen
Young Lau Kin-Ming
Shawn Yue
Young Chan Wing-Yan
Xiao Yaxuan
May
Chapman To
Silly Keung
Gordon Lam
Inspector B
Berg Ng
Senior Inspector Cheung
Dion Lam Dik-On
Del Piero
Tony Ho
Suspect
Courtney Wu
Stereo Shop Owner
Benjamin Yuen
CIB Team
Wong Chi-Wang
CIB Team
Tam Kon-Chung
CIB Team
Lai Chi-Wai
Sam's Follower