The Obscene Extreme festival, shortened as OEF, is an annual music festival in the Czech Republic, that focuses on extreme metal subgenres grindcore and death metal, as well as hardcore punk. It was founded in 1999 as a birthday party by Miloslav "Čurby" Urbanec. It was described by Vice as "Europe's craziest grindcore party". It is noted by the Czech Radio for its "exceptionally tolerant and friendly atmosphere". The festival offers exclusively vegetarian and vegan food within its premises since its inception.
Several well-known metal bands have performed at OEF over the years, such as: Napalm Death, Possessed, Obituary, Sodom, Immolation, Grave, Suffocation, Vader, Incantation, Terrorizer, Exhumed, Asphyx, Morgoth, Brujeria, Sinister, Nuclear Assault, Hirax, Vital Remains, Eyehategod, Krisiun, and Municipal Waste to name a few.
- Jaroslav Špulák, Právo. Organizátor festivalu Obscene Extreme Miloslav "Čurby" Urbanec: Našimi sponzory jsou fanoušci (in Czech). Právo. 18 July 2018.
- Kim Kelly. Europe's Craziest Grindcore Party Heads to North America: Meet the Man Behind Obscene Extreme. Vice. 22 March 2015.
- Viktor Polák. Čurby v Echu o Obscene Extreme: Vidět kapely naživo je úplně zásadní. Czech Radio. 26 June 2017.
- Obscénně a extrémně již po dvacáté: V areálu žádné maso (in Czech). 01.07.18. spark-rockmagazine.cz.