The German market will be at the Peace Gardens until Christmas Eve
Market traders have criticised a decision to put a German market in one of Sheffield's busiest areas, saying it will damage their business.
Castle Market traders say the arrival of the German market at Peace Gardens will take Christmas trade from them.
Graham Longden, from the Market Traders' Association, said putting the market at the opposite end of the city centre to Castle Market was unfair.
The council said the German market did not pose a threat to Castle Market.
Mr Longden told BBC News: "It's not right. We are there 52 weeks out of the year and then these people come into the best areas.
"Our traders down that end of the town have struggled over the year and then at the time when they should be able to take money at Christmas they bring these markets in an again. It's taken [people] away from our area."
Andy Ward, the council's markets general manager, said: "We look in conjunction with city centre management to bring specialist markets into Sheffield throughout the year to enhance the retail offering in Sheffield and bring more people into Sheffield, which benefits everybody."
Mr Ward said the German market only had 14 stalls and sold different goods to those available at Castle Market.
He said if Castle Market traders were willing to sell goods such as German mulled wines and grilled sausages then they could be considered for a place on any specialist markets in the future.