| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. Dolmatov vs J L Arnason |
| 1-0 | 44 |
1977 |
EU-ch 7778 U20 | B40 Sicilian |
| 2. J L Arnason vs Kasparov |
 | 0-1 | 40 |
1977 |
Cagnes sur mer | B84 Sicilian, Scheveningen |
| 3. J L Arnason vs Miles |
 | 0-1 | 50 |
1978 |
Reykjavik | B42 Sicilian, Kan |
| 4. Lombardy vs J L Arnason |
| 1-0 | 37 |
1978 |
It (open) | B33 Sicilian |
| 5. G Bordonada vs J L Arnason |
 | 1-0 | 33 |
1978 |
Buenos Aires ol (Men) | B33 Sicilian |
| 6. J L Arnason vs Larsen |
 | 0-1 | 27 |
1978 |
Reykjavik | C34 King's Gambit Accepted |
| 7. Jansa vs J L Arnason |
 | 1-0 | 37 |
1979 |
Polanica Zdroj | C72 Ruy Lopez, Modern Steinitz Defense, 5.O-O |
| 8. Vasiukov vs J L Arnason |
| 1-0 | 74 |
1979 |
Prague Bohemians | C76 Ruy Lopez, Modern Steinitz Defense, Fianchetto Variation |
| 9. J L Arnason vs Balashov |
| 0-1 | 30 |
1980 |
Sochi | C91 Ruy Lopez, Closed |
| 10. J L Arnason vs R Byrne |
| 0-1 | 54 |
1980 |
Reykjavik | B92 Sicilian, Najdorf, Opocensky Variation |
| 11. Vaganian vs J L Arnason |
| 1-0 | 28 |
1980 |
Sochi | D19 Queen's Gambit Declined Slav, Dutch |
| 12. J L Arnason vs Petursson |
| 0-1 | 59 |
1980 |
Reykjavik | C82 Ruy Lopez, Open |
| 13. J L Arnason vs Panno |
| 0-1 | 35 |
1980 |
Lone Pine | B42 Sicilian, Kan |
| 14. Larsen vs J L Arnason |
 | 1-0 | 46 |
1980 |
Lone Pine | A20 English |
| 15. Ribli vs J L Arnason |
| 1-0 | 42 |
1980 |
Malta ol (Men) | A07 King's Indian Attack |
| 16. J L Arnason vs Kasparov |
 | 0-1 | 58 |
1980 |
Dortmund | B92 Sicilian, Najdorf, Opocensky Variation |
| 17. J L Arnason vs Suetin |
| 0-1 | 39 |
1980 |
Sochi | B42 Sicilian, Kan |
| 18. Adianto vs J L Arnason |
| 1-0 | 36 |
1980 |
Wch U20 | B83 Sicilian |
| 19. Van der Wiel vs J L Arnason |
 | 1-0 | 37 |
1980 |
Sochi | B83 Sicilian |
| 20. J L Arnason vs Alburt |
| 0-1 | 45 |
1980 |
Lone Pine | B03 Alekhine's Defense |
| 21. J L Arnason vs Keene |
  | 0-1 | 34 |
1981 |
London (England) | B06 Robatsch |
| 22. Miles vs J L Arnason |
| 1-0 | 69 |
1981 |
Manchester | A56 Benoni Defense |
| 23. L Shamkovich vs J L Arnason |
| 1-0 | 58 |
1981 |
Lone Pine | B90 Sicilian, Najdorf |
| 24. Igor Ivanov vs J L Arnason |
| 1-0 | 44 |
1981 |
Lone Pine | A65 Benoni, 6.e4 |
| 25. J L Arnason vs Romanishin |
| 0-1 | 33 |
1981 |
Lone Pine | B46 Sicilian, Taimanov Variation |