The average price in the month for a home was £163,751 - a one per cent decrease on July.
But the drop does not reverse the longer-term trend, which has seen property prices in the area grow by 11.6 per cent over the last year.
Over the 12 months, the average sale price of property in Barnsley rose by £17,000 putting the town 13th among Yorkshire and the Humber’s 21 local authorities with price data for annual growth.
First-time buyers in Barnsley spent an average of £145,000 on their property - £15,000 more than a year ago, and £42,000 more than in August 2017.
By comparison, former owner-occupiers paid £183,000 on average in August - 26.4 per cent more than first-time buyers.
Owners of flats saw the biggest fall in property prices Barnsley in August - they dropped 1.1 per cent in price, to £91,129 on average.