| 1991 Estoril Open | |
|---|---|
| Date | 1–8 April |
| Edition | 2nd |
| Category | World Series |
| Draw | 32S / 16D |
| Prize money | $337,500 |
| Surface | Clay / outdoor |
| Location | Oeiras, Portugal |
| Champions | |
| Singles | |
 Sergi Bruguera[1] | |
| Doubles | |
 Paul Haarhuis / Mark Koevermans[2] | |
The 1991 Estoril Open was a tennis tournament played on outdoor clay courts. This event was the 2nd edition of the Estoril Open, included in the 1991 ATP Tour World Series. The event took place at the Estoril Court Central, in Oeiras, Portugal, from 1 April until 8 April 1991.[3]
- ^ "1991 Estoril – Singles draw". Association of Tennis Professionals (ATP).
- ^ "1991 Estoril – Doubles draw". Association of Tennis Professionals (ATP).
- ^ John Barrett, ed. (1992). The International Tennis Federation World of Tennis 1992. London: CollinsWillow. pp. 118, 135. ISBN 9780002184304.