Pedro Martínez started playing tennis when he was five. He already celebrated his first successes on the Junior Tour. In 2014 he was in the main fields of three of the four Junior Grand Slam tournaments . In doubles at the Australian Open , he achieved his best result with the semi-finals. In the junior world rankings he reached 16th place in January 2015 and thus his best ranking.
Martínez appeared regularly with the professionals from 2015 and initially played tournaments of the third-class ITF Future Tour . In the middle of the year he reached two finals in a row. In doubles, he won five future titles by the end of the year. He finished the year in singles in 678 and in doubles in 553 in the world rankings . In 2016 he won four futures from six finals and was able to take part in the higher endowed Challengers at the end of the year . There he made a first respectable success in Meknes with his semi-finals. In the world rankings, he was just outside the top 300. In 2017 Martínez managed to win another three Future titles in individual, but remained less successful with Challengers and stagnated in the world rankings. In doubles he won eight futures and also reached the Challenger finals in Pune , so that he was in 208th place at the end of the year.
In 2018 he was in a Challenger final for the second time in Bangkok , where he lost again. The Spaniard made his debut on the ATP World Tour with a successful qualification in Marrakech . There he lost to João Sousa at the beginning . In July 2018 he won his first Challenger title in Båstad . With position 174 in singles and 155 in doubles, he also achieved his previous top positions in the ranking list in 2018.