The 1986 FIFA World Cup knockout stage was the second and final stage of the 1986 FIFA World Cup finals in Mexico.
The ties in each round were played over a single match; in the event that scores were level after 90 minutes, the teams would play an additional 30 minutes of extra time, divided into two 15-minute halves, to determine the winner.
If the scores remained level after extra time, the teams would contest a penalty shootout.
A third place match was also held on the day before the final, between the two losing teams of the semi-finals.
The following table published in Section 28 of the tournament regulations, shows the different options to define the rivals of the winners of groups A, B, C and D. As both were European teams, this was already set pre-match as the second consecutive World Cup in which European teams finished third.