Hunts which pursue foxes illegally after the ban may not be covered by their insurance if anyone gets hurt.
Most hunts say they will act within the law
The Association of British Insurers (ABI) says public liability policies may not cover hunts judged to have intentionally broken the law.
But it would be for the courts, rather than insurers, to decide if a hunt had set out to act illegally, the ABI said.
It will be illegal to hunt foxes with dogs in England and Wales as of 0001 GMT on Friday 18 February.
Most hunts say they will continue to meet after the ban comes into force but will try to hunt within the law.
This could include drag hunting, hunting rabbits or rats instead of foxes or using no more than two dogs to flush out a fox to a gun or a bird of prey.
But a few hunts have signalled their intention to continue hunting foxes as normal, in defiance of the ban.
The ABI says this could cause "problems" with their public liability insurance policies.
Spokesman Malcolm Tarling said: "Insurers expect their policy holders to be involved in legal activities. If something was clearly shown by the courts to be illegal, it certainly could have implications for a claim."
But he said the fact a hunt was illegal would not automatically mean it would not be covered.
He said the full insurance implications of illegal hunting would not become clear until the new law had been tested in the courts.
He added: "We're entering uncharted and untested territory here. Insurers will have to look at the circumstances of individual claims."