There are at least 10 bands playing various kinds of metal (most of them death metal) of that name. The most popular of them was formed in 1990 in United Kingdom playing doom metal influenced death metal

Ordered by date of formation:

1. Decomposed from United States of America (Corpus Christi, TX), formed in 1987. Currently the band is split up. They were playing thrash metal with hardcore influences. They released only 1 demo (Demo in 1988).

2. Decomposed from France, formed in 1989. They have changed their name to Occult in 1991. They were playing death metal. Under name Decomposed they released only 1 demo (Inner Destruction in 1991).

3. Decomposed from Spain, formed in 1989. They have changed their name to Rotten Flesh in 1991, then to Undivine in 1993 and finally to Blazemth in 1995. They were playing death metal. Under name Decomposed they released only 1 demo (Defective Birth in 1990).

4. Decomposed from United Kingdom, formed in 1990 - probably the most famous and influential band under that name. The band is split up, before their demise they were signed to Candlelight Records. They were playing death metal mixed with doom metal - the music was slow and brutal, yet with unique atmosphere. They released 2 demos (Sermons Of Morbidity in 1990 and Ego Sum Lex Mundi in 1991), 1 EP (The Funeral Obsession in 1992) and 1 full length (Hope Finally Died... in 1993).

5. Decomposed from United States of America (Monsey, NY), formed in 1991. Currently the band is split up. They were playing death metal. They released only 1 demo (Demo #1 in 1991).

6. Decomposed from United States of America (Los Angeles, CA) (also known as L.A.'s Decomposed), exact formation date is unknown. The band is currently split-up, they were signed to Roughage Records. They were playing death metal. They released 1 demo (Demo '92 in 1992) and 1 split album (The Heralds of Oblivion vol. 1 in 1993, 3 tracks/15 total, with Demolition, Catalepsy, Brainstorm, and Mutilage).

7. Decomposed from Chech Republic, formed in 1993. Currently the band is active and signed to Bomb Jack label. They are playing death metal. Between 1999 and 2005 they were inactive due to lack of guitarists. They released 3 demos (And Everybody Love Their Murderers in 1994, Mystery in 1995, Decomposition in 1998), 2 split albums ( Malignus Morbus/Labyrinth Of Lights with Malignant Tumour in 1995 - 2 tracks/9 total, Overcome Fear/Meeting The Life with Psychopathia in 1997 - 12 tracks/22 total) and 1 EP (Labyrinth Of Lights in 1995).

8. Decomposed from United States of America (Pennsylvania), formed in 1999. Currently the band is active and signed to Worldeater Records. They are playing death metal. They released only 1 full length (Torn From The Womb in 2006).

9. Decomposed from Indonesia, formed in 2001. Currently the band is active and signed to Flesh Blood Records. They are playing brutal death metal. They released only 1 EP (Putrid Stench Purulency in 2002) but they have also appeared on various compilations.

10. Decomposed from Greece, formed in 2002. Currently the band is active. They are playing death metal. They released only 1 demo (Unknown Creation in 2004).