The 1990 Philippine Basketball Association (PBA) Third Conference was the third and last conference of the 1990 PBA season.
It started on September 30 and ended on December 20, 1990.
The tournament is a two-import format, which requires each team to have two American reinforcements.
Three teams finished tied for second.
The three teams were ranked via head-to-head quotient, with the best performing team drawing a bye to the second round.