The first round of the 1999–2000 UEFA Cup was played from 14 to 30 September 1999.
[1] The round included 38 winners from the qualifying round, 16 losing teams from the Champions League third qualifying round, 3 winners of the Intertoto Cup and 39 new entrants.
This narrowed the clubs from 96, down to 48 teams in preparation for the second round.
[2][3][4] Notes The seeding groups were as follows:[5] Steaua București won 5–2 on aggregate.
Deportivo La Coruña won 2–1 on aggregate.
IFK Göteborg won 2–1 on aggregate.
Levski Sofia won 3–0 on aggregate.
Inter Bratislava won 3–1 on aggregate.
5–5 on aggregate; Hapoel Haifa won on away goals.
West Ham United won 6–1 on aggregate.