Searchlight, the Anti-Fascist organisation, said the event took place last weekend at a community hall in a suburb of Coventry.
Hundreds of police had earlier been involved in an operation to prevent a large-scale rally taking place in South Wales. Almost 1,000 skinheads, including contingents from Germany, Holland and France, were stopped by police patrols and turned back.
Gerry Gable, editor of the organisation's magazine, Searchlight, said that a small hardcore group of skinheads had re-routed to Coventry, where the concert took place in the evening.
He said: "Until then, the police operation had been first-class. Why did the wheel come off the wagon in the West Midlands?"
The event, intended to take place in the Welsh valleys, had been widely advertised in far-right literature across Europe and skinhead bands from the United States and Germany had been invited to play.
But Searchlight was able to alert the police who ran a special control- room in South Wales for two weeks, monitoring the planned event.
Glenys Kinnock, the South Wales European Parliament MP, called on the authorities to make every effort to stop the concert taking place.
Last week, a 29-year-old Cardiff man was arrested and charged with public order offences after police raided his flat and seized weapons and literature.
Members of an American band that had flown to Britain from Oregon to take part were turned back by immigration officials.
On Saturday, as the skinheads tried to find an alternative venue, a huge police operation led by the South Wales and Leicestershire forces helped to contain them as they moved east, over the English border and into the Midlands.
Warwickshire Police had monitored a group of neo-Nazis who had gathered outside a pub to the east of Coventry. "We were aware of their presence but there wasn't any trouble," said a spokeswoman for the force.
But Searchlight said this group then met up with other skinheads at a hall, two miles away in Coventry, in the West Midlands force area. Police were not present at the event nor were they called on to attend.
Last night, Mr Gable said that the anti-fascist movement was nevertheless delighted that the full-scale rally which had been planned by the racist Blood and Honour organisation had failed to go ahead as planned.
He said: "I think our operation has been a success because there has been an arrest in Wales and exclusions of some of the Americans. No foreign bands were able to play in the final event and the numbers were reduced from up to 1,000 to less than 150."
The failings of the rally will have caused a considerable loss of face for the British skinheads who were once revered by their overseas counterparts but have been repeatedly unable to stage large-scale concerts which are commonplace in Germany.
Meanwhile, there are fears that members of the far-right Combat 18 group are planning to cause trouble in Denmark this weekend as part of a Nazi commemoration of the anniversary of the death of Rudolf Hess, Hitler's deputy.
The authorities in Roskilde have controversially allowed the event, where supporters dress in Nazi costume and carry flags with swastikas, despite widespread violence when the rally took place in the town two years ago.