Thomaz Koch Open era doubles finals (3-8) Open era doubles finals (3-8)

| Outcome | Date_ | Tournament | Surface | Partner | Opponents_in_the_final |
|---|---|---|---|---|---|
| Runner-up | 1968 | Barcelona , Spain | Clay | José Mandarino | Carlos Fernández Patricio Rodríguez |
| Runner-up | 1969 | London/Queen`s Club , U.K. | Grass | Ove Nils Bengtson | Owen Davidson Dennis Ralston |
| Runner-up | 1971 | Salisbury , U.S. | Carpet | Clark Graebner | Juan Gisbert, Sr. Manuel Orantes |
| Winner | 1971 | Macon , U.S. | Hard | Clark Graebner | Željko Franulović Jan Kodeš |
| Runner-up | 1971 | Hampton , U.S. | Hard (i) | Clark Graebner | Ilie Năstase Ion Țiriac |
| Winner | 1971 | Caracas , Venezuela | Clay | Edison Mandarino | Gerald Battrick Peter Curtis |
| Runner-up | 1972 | Washington, D.C. , U.S. | Carpet | Clark Graebner | Tom Edlefsen Cliff Richey |