| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. DeFirmian vs J Costa |
| ½-½ | 22 |
1986 |
Biel (Switzerland) | D28 Queen's Gambit Accepted, Classical |
| 2. J Costa vs Geller |
| 0-1 | 34 |
1987 |
Bern | C69 Ruy Lopez, Exchange, Gligoric Variation, 6.d4 |
| 3. M Muresan vs J Costa |
| 0-1 | 45 |
1987 |
Biel schev | A30 English, Symmetrical |
| 4. J Costa vs Judit Polgar |
 | 0-1 | 22 |
1987 |
Biel-A | A31 English, Symmetrical, Benoni Formation |
| 5. Szabo vs J Costa |
| 1-0 | 34 |
1987 |
Bern | D97 Grunfeld, Russian |
| 6. J Costa vs M Muresan |
| ½-½ | 72 |
1987 |
Biel schev | D10 Queen's Gambit Declined Slav |
| 7. Zsuzsa Polgar vs J Costa |
 | 1-0 | 28 |
1987 |
San Bernardino | D05 Queen's Pawn Game |
| 8. Judit Polgar vs J Costa |
 | 1-0 | 32 |
1987 |
Biel-A | C33 King's Gambit Accepted |
| 9. Nunn vs J Costa |
| 1-0 | 37 |
1987 |
Lugano op | C41 Philidor Defense |
| 10. Anand vs J Costa |
 | ½-½ | 99 |
1988 |
Biel | C41 Philidor Defense |
| 11. M Litinskaya-Shul vs J Costa |
| ½-½ | 57 |
1988 |
Biel-B | D61 Queen's Gambit Declined, Orthodox, Rubinstein Attack |
| 12. N Gaprindashvili vs J Costa |
| ½-½ | 44 |
1988 |
It (cat.8) | D61 Queen's Gambit Declined, Orthodox, Rubinstein Attack |
| 13. J Costa vs Barbero |
| 0-1 | 38 |
1988 |
It (open) | A90 Dutch |
| 14. J Costa vs Barbero |
| ½-½ | 21 |
1989 |
It (open) | A46 Queen's Pawn Game |
| 15. J Costa vs P Lukacs |
| ½-½ | 57 |
1990 |
Elekes mem | D43 Queen's Gambit Declined Semi-Slav |
| 16. J Costa vs K Spraggett |
| 0-1 | 39 |
1990 |
Biel | A45 Queen's Pawn Game |
| 17. Chiburdanidze vs J Costa |
| 1-0 | 55 |
1990 |
Biel-B | B00 Uncommon King's Pawn Opening |
| 18. J Gallagher vs J Costa |
| 0-1 | 25 |
1990 |
Biel-B | C30 King's Gambit Declined |
| 19. J Costa vs Vyzmanavin |
| 0-1 | 33 |
1991 |
Gelsenkirchen (Germany) | E20 Nimzo-Indian |
| 20. Kramnik vs J Costa |
 | 1-0 | 41 |
1991 |
WchT U26 | D35 Queen's Gambit Declined |
| 21. Smyslov vs J Costa |
| 1-0 | 59 |
1991 |
Gelsenkirchen [Ribli,Z | A13 English |
| 22. Barbero vs J Costa |
| 1-0 | 41 |
1991 |
It (cat.4) | D50 Queen's Gambit Declined |
| 23. J Costa vs Shabalov |
| ½-½ | 39 |
1992 |
It (open) | A70 Benoni, Classical with 7.Nf3 |
| 24. J Costa vs Kramnik |
 | 0-1 | 26 |
1992 |
Ch Europe (team) | D47 Queen's Gambit Declined Semi-Slav |
| 25. S Zoister vs J Costa |
| 0-1 | 29 |
1992 |
Suhr op 4 | C30 King's Gambit Declined |