Most populated Cities in Puerto Rico City Population Time Zone San Juan 418,140 APT Bayamon 203,499 APT Carolina 170,404 APT Ponce 152,634 APT Caguas 86,804 APT Guaynabo 81,360 APT Mayagueez 78,647 APT Trujillo Alto 54,189 APT Trending on WorldAtlas