* Andi Deris, Vocalista (1994-presente)
* Michael Weikath, Guitarra (comienzo-presente)
* Sascha Gerstner, Guitarra (2002-presente)
* Markus Grosskopf, Bajo (comienzo-presente)
* Dani Löble, Batería (2005-presente)

Miembros anteriores

* Piet Sielck,guitarrista (comienzo-1982)
* Kai Hansen, Vocalista (comienzo-1986), Guitarra (comienzo-1989)
* Michael Kiske, Vocalista (1987-1993)
* Roland Grapow Guitarra (1988-2001)
* Ingo Schwichtenberg, Batería (comienzo-1994)†
* Uli Kusch, Batería (1994-2001)
* Mark Cross, Batería (2001-2003)
* Stefan Schwarzmann, Batería (2003-2005)

Discografía

Estudio

* Helloween (1985)
* Walls of Jericho (1985)
* Keeper Of The Seven Keys Part 1 (1987)
* Keeper Of The Seven Keys Part 2 (1988)
* Pink Bubbles Go Ape (1991)
* Chameleon (1993)
* Master Of The Rings (1994)
* The Time Of The Oath (1996)
* Better Than Raw (1998)
* Metal Jukebox (1999)
* The Dark Ride (2000)
* Rabbit Don't Come Easy (2003)
* Keeper Of The Seven Keys - The Legacy (2005)
* Gambling With The Devil (2007)

Singles

* "Judas" (1986)
* "Future World" (1987)
* "Dr. Stein" (1988)
* "I Want Out" (1988)
* "Kids Of The Century" (1991)
* "Number One" (1991)
* "When The Sinner" (1993)
* "Step Out Of Hell" (1993)
* "Windmill" (1993)
* "I Don't Wanna Cry No More" (1993)
* "Mr. Ego" (1994)
* "Where The Rain Grows" (1994)
* "Perfect Gentleman" (1994)
* "Sole Survivor" (1994)
* "The Time Of The Oath (Single)" (1996)
* "Power" (1996)
* "Forever And One" (1996)
* "Forever And One Live" (1996)
* "I Can" (1998)
* "Hey Lord" (1998)
* "Lay All Your Love On Me" (1999)
* "If I Could Fly" (2000)
* "Mr. Torture" (2000)
* "Just A Little Sign" (2003)
* "Mrs God" (2005)
* "Light The Universe" (2006)
* "As Long As I Fall" (2007)
* "Find my Freedom" (2008)

Directos

* Keepers Live (1989)
* I Want Out Live (1989)
* Live In The U.K. (1989)
* High Live (1996)
* Keeper Of The Seven Keys - The Legacy World Tour 2005/2006 - Live In Sao Paulo (2007)
* Hellish Rock 07/08 (2008)

Compilaciones

* Helloween/Walls Of Jericho/Judas (1988)
* Pumpkin Tracks (1989)
* The Best, The Rest, The Rare (1991)
* Keeper Of The Seven Keys Parts 1 & 2 (1993)
* Pumpkin Box (1998)
* Karaoke Remix Vol. 1 (1998)
* Karaoke Remix Vol. 2 (1998)
* Metal Jukebox (1999)
* Treasure Chest (2002)
* Buried Treasure (2002) (edición limitada)
* The Singles Box 85-92 (2006)