The cull area would cover 288km² (111 sq-miles)
A judge has rejected a legal challenge to the assembly government's decision to cull badgers in part of south west Wales.
Animal charity the Badger Trust applied to the High Court for a judicial review of the planned cull, which aims to combat bovine TB infection.
The cull area would cover north Pembrokeshire, and a small part of Ceredigion and Carmarthenshire.
Mr Justice Lloyd Jones said the assembly government's order was lawful.
The cull is expected to take place over the next few months.
David Williams, chairman of the Badger Trust, said: "Whilst we are disappointed that, although permission was granted, the minister's order was not quashed, this was not a simple case about winning or losing.
"Important issues emerged in these proceedings, which ought to give the minister serious cause for thought before proceeding with any cull.
"We hope that compassion and sense will prevail in light of the latest evidence. Meanwhile, we will carefully consider appealing the judgment."
The assembly government has said compensating farmers cost the taxpayer nearly £24m last year and cattle and badgers were the main sources of the disease.
Reacting to Friday's ruling Rural Affairs Minister Elin Jones said: "We welcome the court's decision.
"Bovine TB is one of the biggest problems facing cattle farmers across Wales, and we have to tackle all sources of the disease.
"We are dealing with an epidemic that has serious consequences for us all and we must stamp it out.
"Over the past three years, with advice from experts, we have put in place a comprehensive programme to eradicate TB across Wales.
"We need to read and digest this verdict. In the meantime, we will continue with the preparations in the pilot area."
Opponents said it was not proved that a cull of badgers would significantly contribute to the eradication of bovine TB.
Rock star Brian May was among protesters who backed the animal charity's opposition and spoke out against the plan.
After the ruling, he warned the battle to overturn the TB Eradication Order (Wales) 2009 would continue.
"This is a disappointment, of course. But not just for thousands of innocent badgers," he said.
"The decision to cull cannot lead to any significant long-term gain in the fight against bovine TB, even with the complete extermination of our native badgers."
He added: "I believe all this will be seen in a few years time for what it is... a tragic wrong turn which did nothing to solve the problem of TB in cattle."
FUW vice president Brian Walters, said: "This issue is not just about killing badgers - it's about preventing them and our cattle suffering from this terrible and costly disease.
"It is not a time for celebration - it's time for us to do all we can to stop all further suffering of cattle and wildlife affected by TB.
"Obviously, we are glad that the judge has ratified the considered views of the veterinary establishment and those scientific experts who have advised the assembly's rural affairs minister."
Mr Justice Jones heard two days of submissions during a hearing in Swansea last month.