Seminario started his career in 1954 playing for
Deportivo Municipal where he played until 1959. During this time he made 19 appearances for the
Peru national team. On 17 May 1959 he scored a
hat-trick against
England in a 4–1 win, in
Lima. In 1959 he moved to Europe, joining
Sporting CP of
Portugal, where he would play 50 matches and score 21 goals, and be nicknamed
Expresso de Lima. In 1961 he moved on to join
Real Zaragoza in Spain where he became the
top scorer in
La Liga (with 25 goals in 30 matches) for the
1961–62 season. Before he was sold to Italy, he would play 8 matches and score 8 goals in the Zaragoza. In 1963 he joined
Fiorentina of Italy before returning to Spain in 1964 to play for
Barcelona where he was part of the squad that won the
Inter-Cities Fairs Cup in
1965–66. He later had a spell with
Sabadell before returning to
Peru in 1969 to play for
Atlético Grau. ==Career statistics==