The 2018 Peruvian promotion play-offs or Cuadrangular de Ascenso 2018 was held in December 2018 with all games being played at Estadio Miguel Grau, Callao.
The play-offs determined the third and fourth team to be promoted to the Torneo Descentralizado following that tournament's expansion.
The teams place 2nd and 3rd in the 2018 Peruvian Segunda División and 2018 Copa Perú took part in the promotion play-offs.
The top two placed team in the play-offs gained promotion in the 2019 Torneo Descentralizado and the bottom two qualified to the 2019 Peruvian Segunda División.
At the beginning of the 2018 season, it was announced that the teams that finished 2nd and 3rd in the bottom two tiers of the Peruvian football league system would compete on the promotion play-offs at the end of the year to decide which two teams would receive the expansion slots.