Los Ticos saw their World Cup campaign come to an end on Saturday evening in Salvador, where they suffered a 4-3 loss on penalties after holding the Dutch to a 0-0 draw after extra time.
More than 1,000 supporters had gathered to watch the encounter in the Costa Rican capital San Jose when violence unfolded in the city's main square.
The Costa Rican Public Security Ministry released a statement reporting that Red Cross responders attended to three victims from a fight in the capital's Plaza de la Democracia. Two of those suffered stab wounds, including one who was left stricken with a knife lodged in his back after the bloody encounter.
Police in the Central American nation have arrested eight people suspected of being involved in the disturbance, though the cause of the brawl is as yet unknown and no update has been given on the condition of those injured.
The trouble came amid an otherwise peaceful gathering, where crowds flocked to see Costa Rica denied by two Tim Krul saves in the shootout after the keeper had replaced Jasper Cillessen in the last few seconds of the game.