| | Joker's Wild (encrypted) | 1988 | Sigma | jokrwild | | 0.00 |
 | Juuouki (set 1, Japan, FD1094 317-0065) (clone of: altbeast) | 1988 | Sega | altbeastj1 | | 0.00 |
| Juuouki (set 3, Japan, FD1094 317-0068) (clone of: altbeast) | 1988 | Sega | altbeastj3 | | 0.00 |
| Juuouki (set 7, Japan, 8751 317-0077) (clone of: altbeast) | 1988 | Sega | altbeastj | | 0.00 |
| | Kabuki-Z (Japan) (clone of: kabukiz) | 1988 | Kaneko / Taito Corporation | kabukizj | Fighter / 2.5D | 0.00 |
| | Kabuki-Z (World) | 1988 | Kaneko / Taito Corporation Japan | kabukiz | Fighter / 2.5D | 6.94 |
 | Kageki (Japan) (clone of: kageki) | 1988 | Kaneko / Taito Corporation | kagekij | Fighter / Versus | 0.00 |
| Kageki (US) | 1988 | Kaneko / Taito America Corporation (Romstar license) | kageki | Fighter / Versus | 8.50 |
![Kanatsuen no Onna [BET] (Japan 880905)](../snapsmall/MS_2373.html) | Kanatsuen no Onna [BET] (Japan 880905) | 1988 | Panac | kanatuen | Tabletop / Mahjong *Mature* | 0.00 |
 | Kick Off (Japan) | 1988 | Jaleco | kickoff | Sports / Soccer | 3.17 |
 | Kickle Cubele (clone of: kikcubic) | 1988 | bootleg | kikcubicb | | 0.00 |
 | Kikiippatsu Mayumi-chan (Japan) | 1988 | Sanritsu / Victory L.L.C. | mayumi | Tabletop / Mahjong *Mature* | 2.00 |
 | Kitten Kaboodle | 1988 | Konami | kittenk | Puzzle | 3.33 |
 | Konami '88 (clone of: 88games) | 1988 | Konami | konami88 | Sports / Track & Field | 0.00 |
| | Konek-Gorbunok | 1988 | Terminal | konek | | 7.00 |
 | Koukuu Kihei Monogatari - The Legend of Air Cavalry (Japan) (clone of: chopper) | 1988 | SNK | legofair | Shooter / Flying Vertical | 0.00 |
 | Kuri Kinton (Japan) (clone of: kurikint) | 1988 | Taito Corporation | kurikintj | | 0.00 |
| Kuri Kinton (US) (clone of: kurikint) | 1988 | Taito America Corporation | kurikintu | | 0.00 |
| Kuri Kinton (World) | 1988 | Taito Corporation Japan | kurikint | Platform / Fighter Scrolling | 5.50 |
| Kuri Kinton (World, prototype?) (clone of: kurikint) | 1988 | Taito Corporation Japan | kurikinta | | 0.00 |
