Sin Piedad (Spanish for "No Mercy" or "No Pity", not to be confused with a similarly-titled series of PPV's hosted by WWE) is the collective name of a series of annual lucha libre, or professional wrestling major show promoted by Mexican professional wrestling promotion Consejo Mundial de Lucha Libre (CMLL). The Sin Piedad show is CMLL's end of the year show, held in December. The first show held under the Sin Piedad took place in 2000, although CMLL has traditionally held a major event in December before then. Sin Piedad has been held eleven times so far, with the end of years event in 2005 billed as Juicio Final ("Final Justice") and then 2009 event billed as Sin Salida ("No Escape") instead. In 2008 Sin Pidead was held in August, with no December show being held at all.
The very first Sin Piedad event produced under that name took place on December 15, 2000 in Arena México, in Mexico City, replacing their regularly produced Friday night CMLL Super Viernes ("Super Friday") show. All subsequent Sin Piedad shows have taken place on Friday nights and all in Arena México, CMLL's "home arena". As of the 2012 show a total of 145 wrestlers have competed in 66 matches spread out over the 11 shows. 115 males 15 female and 15 Mini-Estrella competitors have worked the Sin Piedad shows. Atlantis is the wrestlers with the most Sin Piedad matches, ten in total or 91% of all shows so far. Marcela is the female wrestler with most matches, five in total, and Pierrothito is the most frequently featured Mini-Estrella with four matches in total. Demus 3:16 has worked under Sin Piedad shows two different ring names, Pequeño Damián 666 and Demus 3:16, while El Sagrado also worked a Sin Piedad show under his previous identity Genético. 77 wrestlers have only wrestled one Sin Pidedad match so far. The 11 shows has hosted 66 matches so far, six on each except for the 2003 show which only had 5 and the 2008 show which had 7 matches.