Organisers of Bovingdon Market "turned a blind eye" to the fact that up to a quarter of the stall holders were selling fake goods, a court heard this week.
A jury at St Albans Crown Court were told Wendy Fair Markets and its directors took money from stall holders and were not bothered if they were selling counterfeit goods.
The market, held every Saturday and bank holiday at Bovingdon Airfield, has more than 500 stalls selling everything from fresh food and household items to toys, electrical goods and fashion wear.
However, it is alleged that more than 100 stalls have been selling counterfeit goods.
Market operators Wendy Fair Markets and the company's directors Sally Ward, 44, of Woodland Road, Maple Cross, and Nicholas Hobday, 46, from Northamptonshire deny three charges of infringing copyright.
They also deny two charges alleging the unauthorised use of a trademark between September and November 2005 and four of money laundering between June and November 2005.
Two stall holders Louise Taylor, 31, and her partner, Christopher Constantine, 49, of Bardolph Road, Islington, also appeared in court this week.
The court heard Trading Standards officers made 12 test purchases from their stall and found they were selling films that were still being shown in cinemas.
The pair deny infringing copyright by selling copied films between May and November 2005.
David Groome, prosecuting, told the court on Tuesday that "the discs were obviously illegal".
Refering to Ward and Hobday he said: "They must have been aware that counterfeit goods were openly being sold. These directors turned a blind eye, they didn't care as long as they were taking money from the stall holders."
The trial is expected to last three more weeks. The case continues.