Due to the two-month players' strike, the 1981 season was split into two halves, with division leaders of each half facing each other in a temporary best-of-five Division Series format. The winners advanced to the League Championship Series. For the Expos, it would mark their first and only postseason in their existence in Montreal (1969-2004), and they made the most of it by beating the eliminating the defending world champions in five games before meeting the Dodgers in the NLCS.

Game 1 marked the first MLB playoff game outside of the United States, as Steve Rogers allowed just one run over 8 2/3 innings opposite Steve Carlton.

Home teams won each game until Game 5 at Veterans Stadium, where Rogers again got the win and Carlton took his second loss, a 3-0 Expos clincher. Not only did Rogers throw a shutout, but he also delivered a two-run single off Carlton to break up a scoreless tie in the fifth inning. It was an extra measure of satisfaction for the Expos, easing the sting of Mike Schmidt's Game 161 two-run homer in the 11th at Montreal that had secured the NL East title for Philadelphia just one year earlier.

Path to the ALDS: Montreal (30-23) won the NL East second half and Philadelphia (34-21) won the NL East first half

Managers: Jim Fanning, MON; Dallas Green, PHI