The prince is said to have asked RAF officials if he can fly out to the warzone and take part in some active service, reports the Daily Star.
A Whitehall defence source said: ''The brothers are in touch nearly every day but every time William hears from Harry he is left feeling really envious of all his Afghan adventures and wants to share in the action.
''William is a serving officer and has said he wants to go. Although the rule is he cannot be placed in harm's way, they are seeing if they can bring it about before next spring when he has to decide if he's staying on or leaving the Forces to be a full-time royal."
The insider added: "He could do a secret visit of a week or two if the powers that be would allow it.
''We are not talking bombing the Taliban, more like flying fetch-and-carry missions but he could still be involved.''
William will allegedly discuss whether to rejoin the RAF with wife Kate Middleton before the end of the year.
A St James's Palace source said: ''The prince has to decide before the end of the year and will make that decision with his wife.
''He surprised us all when he said he wanted to be a search and rescue pilot. It was entirely his own idea. I would not put it past him to come up with something none of us thought of.''
Prince William and Kate recently completed their nine-day Jubilee tour in Tuvalu.
Prince Harry was said to have been the target of the Taliban when they attacked Camp Bastion earlier this month.