Post-Hardcore, as the name might suggest, is a musical offshoot of the hardcore punk movement. The earliest appearances of the genre were in Washington, DC in the mid- to late 1980s (see the era's releases on Dischord Records for example) and was not widespread until the early 1990s however. Post Hardcore music, as a musical genre, is marked by its precise rhythms and loud guitar based instrumentation and vocal performances that are as often sang as shouted. The genre has developed a unique balance of dissonance and melody. It shares with its hardcore roots an intensity and social awareness and the some of the DIY punk ethic present, but eschews much of the unfocused adolescent rage and sloppy amatuerisms of the music. One of the earliest and most prolific of these bands is DC's Fugazi. The genre also includes bands such as Jawbox, Shudder to Think, Glassjaw, Slint, (post-hardcore with a decided art rock lean) Rodan, Tar, Jesus Lizard, Lard, Big Black, (both with a strong industrial music influence) among others. The genre produced less and less through much of the 1990s and now is nearly vanished from the public eye, though in more underground circles the genre is carried on.

Related genres include both emo and math rock which share a common heritage with post hardcore, though these two genres have since diverged and developed uniquely unto themselves.