The son of Concha Lopez and Eloy Campos, Frank Campos had a brother, Tony Campos, who played in the minor leagues and several international circuits. His brother-in-law Rafael Sangil also played in the minors. Frank played 11 years in professional baseball and had a long career in Cuba as well. In the Cuban Winter League, he was known as Cisco.
Campos debuted with the 1944 Portsmouth Cubs. The 20-year-old hit .296/~.365/.388 with 10 triples (tied for second in the Piedmont League behind Tommy Brown's 11). He stole 14 bases and scored 74 runs, sixth in the league. In 1944-45, Frank only hit .200/?/.238 for Marianao. In '45, Frank batted .323 for Portsmouth, putting him in the top 10 in average. In the 1945-46 Cuban Winter League, Francisco batted .370 and slugged .479 for Marianao. His six triples tied Nap Reyes for the CWL lead. More impressively, he led Marianao in runs (32) and average despite the presence of famous names like Lazaro Salazar, Minnie Minoso, Ray Dandridge, Bobby Estalella and Claro Duany.
Frank played for Regla in the 1946 Cuban summer league, which was a failure. He also spent time with the Puebla Parrots that year but only batted .247/~.302/.321 in 47 games; that was a big year in the Mexican League when major league players were lured south and the top Cuban players and some Negro League stars joined in as well. That fall, he played for an All-Star Cuban team against the Washington Senators when they visited the island. In the 1946-47 winter league season, Cisco only hit .222/?/.304 for Marianao with 3 RBI in 135 AB as the club finished last again.
Returning to Puebla in '47, 23-year-old Campos batted .268/~.363/.356, showing decent OBP skills and driving 7 triples. Overall, he had hit .261/~.343/.343 in his two seasons in the Mexican League. In 1947-48, Cisco played for Alacranes in the Players Federation, hitting .260 and slugging .406 in 96 AB as the fifth outfielder on a team that included Roberto Ortiz, Santos Amaro and Ducky Davenport among its flyhawks. Returning to Portsmouth in '48, he batted .261 with no homers and 24 RBI.
In 1948-49, Campos only hit .227/?/.264 with 5 RBI in 110 AB as the 4th outfielder for the Marianao club. Frank played well in an exhibition against the Philadelphia Athletics in the spring of 1949. Playing for the hometown Havana Cubans in the 1949 Florida International League, Campos batted .338/?/.394 and led the league in batting average. As usual, he did not show much power or steal many bases but his contact hitting that season was exemplary.
For the champion Almendares Blues, Cisco hit just .171/?/.229 in a backup role in the 1949-50 Cuban Winter League as Ortiz and Al Gionfriddo were the main two outfielders and Bill Antonello was used frequently as the third one.
In 1950, Campos was briefly for the Havana Cubans but spent most of the year with the Charlotte Hornets. With Charlotte, the outfielder batted .322/~.381/.399 and was third in the Tri-State League in batting average. He only struck out 12 times in 419 AB. In the 1950-51 Cuban Winter League, Cisco went 0 for 1 for Almendares.
Frank returned to Charlotte in 1951 and batted .363 with a career-high 6 HR and 103 RBI. He led the Tri-State League in average, was fifth in RBI and was named MVP. He joined the 1951 Washington Senators late in the year and went 11 for 26 with three doubles and a triple. In the 1951-52 Cuban Winter League, Francisco hit .302 and slugged .358 for last-place Almendaro, again a 5th outfielder behind other past or future major leaguers, Frank Carswell, Walt Moryn, Ortiz and Wally Post.
Campos spent the entire campaign with the 1952 Senators and hit .259/.278/.330 in 112 AB over 53 games as a pinch-hitter and backup corner outfielder. He was hit in his head by a ball pitched by Bob Lemon, which may have led to his career ending sooner. In the 1952-53 Cuban Winter League, Cisco hit .212 and slugged .295 for Almendares in his last winter ball season. Frank split 1953 between the Senators (1 for 9, 1 walk, 2 RBI in 10 pinch-hit appearances, never playing the field), the Toronto Maple Leafs (.239/~.311/.373, a surprising 3 HR in 67 AB) and the Charleston Senators (.294/~.390/.373). Overall, Campos had batted .279/.298/.367 in the major leagues, showing above-average contact skills and fair power but poor walk ability.
In 1954, Frank wrapped up his career by batting .255 with no home runs and six RBI for the Chattanooga Lookouts.