The following are known Game Genie Codes for Batman: Return of the Joker on Nintendo Game Boy.

• O62-01F-C42
  Start with max of 3 Hit Points
• 102-01F-C42
  Start with max of 8 Hit Points
• 022-07F-F7E
  1 Continue
• 0A2-07F-F7E
  9 Continues
• 00A-B5D-F75
  Infinite Continues
• 05D-A0B-C42
  5 Batarangs on pick-up
• 14D-A0B-C42
  20 Batarangs on pick-up
• 28D-A0B-C42
  40 Batarangs on pick-up
• 009-96E-19E
  Infinite Batarangs on pick-up