He is the son of a former Romanian language teacher and a former football referee Adrian Porumboiu [hu; it; ro], currently a businessman.

With his graduation short movie, A trip to the city, he gets prize II in the Cinefondation section at Cannes International Film Festival.

In 2005, Corneliu writes and directs his first feature film 12:08 East of Bucharest selected in Quinzaine des Realisateurs where he obtained the Camera d'Or Award.

In 2013, the third feature When evening falls on Bucharest or Metabolism, signed by Corneliu Porumboiu, had its premiere at the Locarno Film Festival.

In December 2023, alongside 50 other filmmakers, Porumboiu signed an open letter published in Libération demanding a ceasefire and an end to the killing of civilians amid the 2023 Israeli invasion of the Gaza Strip, and for a humanitarian corridor into Gaza to be established for humanitarian aid, and the release of hostages.