| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. DeFirmian vs J L Arnason |
| 0-1 | 31 |
1973 |
Bunadarbanka (Iceland) | C72 Ruy Lopez, Modern Steinitz Defense, 5.O-O |
| 2. J L Arnason vs J Kristinsson |
| ½-½ | 19 |
1973 |
It | C36 King's Gambit Accepted, Abbazia Defense |
| 3. Dolmatov vs J L Arnason |
| 1-0 | 44 |
1977 |
EU-ch 7778 U20 | B40 Sicilian |
| 4. J L Arnason vs K Mokry |
| 1-0 | 41 |
1977 |
EU-ch 7778 U20 | B51 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 5. J L Arnason vs Kasparov |
 | 0-1 | 40 |
1977 |
Cagnes sur mer | B84 Sicilian, Scheveningen |
| 6. J L Arnason vs K Mokry |
| ½-½ | 31 |
1978 |
Bohemians | B00 Uncommon King's Pawn Opening |
| 7. G Bordonada vs J L Arnason |
 | 1-0 | 33 |
1978 |
Buenos Aires ol (Men) | B33 Sicilian |
| 8. J L Arnason vs G Kuzmin |
| 1-0 | 23 |
1978 |
Reykjavik Iceland ch | C34 King's Gambit Accepted |
| 9. J L Arnason vs Larsen |
 | 0-1 | 27 |
1978 |
Reykjavik | C34 King's Gambit Accepted |
| 10. J L Arnason vs Miles |
 | 0-1 | 50 |
1978 |
Reykjavik | B42 Sicilian, Kan |
| 11. J L Arnason vs Smejkal |
| ½-½ | 52 |
1978 |
Reykjavik | B06 Robatsch |
| 12. J L Arnason vs E Raaste |
| ½-½ | 51 |
1978 |
Telechess ol1 7778 | C16 French, Winawer |
| 13. Lombardy vs J L Arnason |
| 1-0 | 37 |
1978 |
It (open) | B33 Sicilian |
| 14. Vasiukov vs J L Arnason |
| 1-0 | 74 |
1979 |
Prague Bohemians | C76 Ruy Lopez, Modern Steinitz Defense, Fianchetto Variation |
| 15. J L Arnason vs A Planinc |
 | 1-0 | 17 |
1979 |
Rubinstein mem | C78 Ruy Lopez |
| 16. Jansa vs J L Arnason |
 | 1-0 | 37 |
1979 |
Polanica Zdroj | C72 Ruy Lopez, Modern Steinitz Defense, 5.O-O |
| 17. J L Arnason vs P Ostberg |
| ½-½ | 33 |
1979 |
Nordic-ch | C91 Ruy Lopez, Closed |
| 18. J L Arnason vs J Ambroz |
| ½-½ | 39 |
1979 |
Prague Bohemians | C19 French, Winawer, Advance |
| 19. G Timoshchenko vs J L Arnason |
| ½-½ | 41 |
1979 |
Rubinstein mem | B41 Sicilian, Kan |
| 20. J L Arnason vs Filip |
| ½-½ | 41 |
1979 |
Rubinstein Mem | C76 Ruy Lopez, Modern Steinitz Defense, Fianchetto Variation |
| 21. J L Arnason vs Panno |
| 0-1 | 35 |
1980 |
Lone Pine | B42 Sicilian, Kan |
| 22. J L Arnason vs Balashov |
| 0-1 | 30 |
1980 |
Sochi | C91 Ruy Lopez, Closed |
| 23. Larsen vs J L Arnason |
 | 1-0 | 46 |
1980 |
Lone Pine | A20 English |
| 24. Vaganian vs J L Arnason |
| 1-0 | 28 |
1980 |
Sochi | D19 Queen's Gambit Declined Slav, Dutch |
| 25. J L Arnason vs R Henley |
| ½-½ | 31 |
1980 |
Lone Pine | C34 King's Gambit Accepted |