Roman Kowalewski was selected to compete at the 1969 European Rowing Championships where he came 11th in the double sculls with partner Wiesław Długosz. Two years later Kowalewski achieved the same result at the 1971 European championships, this time with Zdzisław Bromek. His consistent performances earned him a place on the Polish Olympic team for the 1972 München Olympics where he finished 12th in the double sculls with Kazimierz Lewandowski. His final international competition came in 1975 when he was part of the Polish crew that rowed in the quadruple sculls. Following his competitive rowing career Kowalewski became a coach as well as the head of the School of Physical Education and Sport at the Szczecin University of Technology. His brother Mirosław was part of Poland’s eight crew at the 1980 Moskva Olympics.