Pedro Nieves' career began in Puerto Rican school tournaments, playing for Colegio Ángeles Custodios. He later moved to study in the United States of America, where he participated in the NAIA Division I with Grand View from 2012 to 2016, reaching the final for the title during his senior year.
In the 2016-17 season he made his professional debut with Cariduros de Fajardo in the PR Professional League, the following season he moved to Greece, defending the colors of Panachaïkī, in the Pro-League. He returned to Puerto Rico for the LVSM 2018, defending the colors of Llaneros de Toa Baja, while the following year he wore the Caribes de San Sebastián jersey.
He returns to play abroad, in the United States of America, on the occasion of the NVA Showcase 2020, in which he participates with LA Blaze and, after also participating in the NVA 2021, then he spends a year in Israel on the Premier League with Eilaboun and then returns to his homeland to play in the Men's Superior Volleyball League from 2022 with the Caribes de San Sebastián, winning a Championship last year and looking for the back to back this season.
He was part of the Puerto Rico U-21 team, in 2016 he debuted with the senior team during the World League. He subsequently won the gold medal at the 2021 North American Championship and then the bronze at the XXIV Central American and Caribbean Games.
He has coached boys & girls in different clubs in PR and in San Diego California in Coast Volleyball Club the past years.