Šmejkal played for Škoda Plzeň in the 1988–89 Czechoslovak First League and represented Dukla Prague in the same competition in the 1989–90 and 1990–91 seasons.

After the establishment of the Czech First League in 1993, Šmejkal played for Plzeň again, by now renamed as Viktoria Plzeň, in the 1993–94 season, before spending three seasons with Slavia Prague, during which time he won the 1995–96 Czech First League.

He then played for Czechoslovakia national under-21 football team, scoring once in twelve appearances between 1988 and 1990.

[1] From 1994 until 1995 Šmejkal represented the Czech Republic internationally and scored three goals in ten appearances.

Having led Sokolov to finishing positions of fifth and fourth in the second tier of Czech football, Šmejkal joined Czech First League side FK Teplice in the summer of 2016, signing a two-year contract.