The 1990–91 season of the Balkans Cup club tournament was the 27th season of the competition. It was won by Romanian side Inter Sibiu in the final against Yugoslav Budućnost Titograd for their first title in the competition.[1]
Quarter-finals
| Team 1 | Agg. | Team 2 | 1st leg | 2nd leg |
|---|---|---|---|---|
17 Nëntori Tirana 
|
1–2 |  Budućnost Titograd
|
0–0 | 1–2 |
Etar Veliko Tarnovo 
|
1–2 |  OFI
|
0–0 | 1–2 |
Inter Sibiu 
|
Bye | — | — | |
Galatasaray 
|
Bye | — | — |
First leg
Second leg
Budućnost won 2–1 on aggregate.
OFI won 2–1 on aggregate.
Semi-finals
| Team 1 | Agg. | Team 2 | 1st leg | 2nd leg |
|---|---|---|---|---|
| Budućnost Titograd
|
1–1 (a) | Galatasaray
|
0–0 | 1–1 |
| OFI
|
2–2 (a) | Inter Sibiu
|
2–1 | 0–1 |
First leg
Second leg
| Galatasaray | 1–1 | Budućnost Titograd |
|---|---|---|
Yücedağ  55' |
Report | Saveljić 75' |
Referee: ? (Bulgaria)
Galatasaray 1–1 Budućnost on aggregate. Budućnost won on away goals.
| Inter Sibiu | 1–0 | OFI |
|---|---|---|
Inter Sibiu 2–2 OFI Crete on aggregate. Inter Sibiu won on away goals.
Finals
| Team 1 | Agg. | Team 2 | 1st leg | 2nd leg |
|---|---|---|---|---|
| Budućnost Titograd
|
0–1 | Inter Sibiu
|
0–0 | 0–1 (a.e.t.) |
First leg
| Budućnost Titograd | 0–0 | Inter Sibiu |
|---|---|---|
Referee: Vutsaras Maletios (Greece)
Second leg
| Inter Sibiu | 1–0 (a.e.t.) | Budućnost Titograd |
|---|---|---|
| Cotora 105' |