New Kids on the Block were most popular from the late 1980s into the early 1990s, with a huge commercial peak around 1988–1991.

Peak popularity years

  • Their big breakthrough came with the album Hangin’ Tough (released 1988), which produced several major hits and pushed them into mainstream teen‑idol status by 1989.
  • The absolute peak of their fame is generally placed between about 1989 and 1991, when they dominated U.S. charts, toured heavily, and were one of the top‑grossing live acts in the country.

What “popular” looked like for NKOTB

  • During these peak years, they scored multiple top‑10 singles like “Hangin’ Tough,” “I’ll Be Loving You (Forever),” and “You Got It (The Right Stuff),” and their fan club and merchandise sales were enormous.
  • By 1989–1990 they were described as the most successful act of their kind in the U.S., with massive tours, TV exposure, and even a cartoon series.

After the first wave

  • Their popularity declined in the early 1990s, and the group initially disbanded in the mid‑1990s after their first major run.
  • They later enjoyed a nostalgia‑driven resurgence starting in the late 2000s, with reunion tours and new releases bringing renewed attention, though their cultural “moment” is still most strongly tied to the late ’80s and early ’90s.

TL;DR: When people ask “when were New Kids on the Block popular?” they almost always mean that original boy‑band explosion from about 1988 to 1991, when they were everywhere in pop culture.

Information gathered from public forums or data available on the internet and portrayed here.