Practice What You Preach is the third studio album by American thrash metal band Testament, released in August 1989 via Atlantic/Megaforce. Propelled by the singles "Greenhouse Effect", "The Ballad" and the title track "Practice What You Preach", this album was a major breakthrough for Testament, achieving near gold status and becoming the band's first album to enter the Top 100 on the Billboard 200 chart.

Testament is an American thrash metal band from Berkeley, California. Formed in 1983 under the name Legacy, the band's current lineup comprises rhythm guitarist Eric Peterson, lead vocalist Chuck Billy, lead guitarist Alex Skolnick, bassist Steve Di Giorgio and drummer Chris Dovas. Testament has experienced many lineup changes over the years, with Peterson being the only remaining original member, though they have since reunited with Skolnick, who had been out of the band from 1992 to 2005. Billy has been a member of Testament since 1986, when he replaced original singer Steve "Zetro" Souza, who had left to replace Paul Baloff in Exodus. He and Peterson are the only members to appear on all of Testament's studio albums, with the latter being the only constant member overall. The band has released thirteen studio albums, four live albums, five compilation albums, thirteen singles and three DVDs. They are estimated to have sold over 1.4 million albums in the United States since the beginning of the SoundScan era, and over 14 million copies worldwide as of 2016.