Martinez was born in 1941 in Santo Domingo, Dominican Republic. He received his Bachelor of Business Administration degree from the University of Miami in 1962 and his J.D. from the University of Miami School of Law in 1965.
Martinez served in the United States Naval Reserve from 1964 to 1993, and was a Navy legal officer from 1965 to 1968.
Martinez served as a clerk in private practice in 1965. He was an Assistant U.S. Attorney for the Southern District of Florida from 1968 to 1970. Martinez was in private practice in Florida from 1970 to 2002. From 1972 to 1974, he was regional director of the Office for Drug Abuse Law Enforcement of the Department of Justice.
President George W. Bush nominated Martinez to the United States District Court for the Southern District of Florida on January 23, 2002, to the seat vacated by Edward B. Davis. Confirmed by the Senate on September 13, 2002, he received commission on September 17, 2002.
Martinez was the judge in Sinaltrainal v. Coca-Cola.
