Overall, 44 per cent of retailers said sales were up on the same period last year, compared with 37 per cent who said they were down - a positive balance of 7 per cent. In June, there was a positive balance of 9 per cent.
Warm weather and the World Cup drove sales of food and electricals, and grocers filed their most positive results since Christmas. DIY, furniture and carpet retailers were among those who performed less well.
More retailers than not said sales were below their expectations for the time of year. The survey also suggested that sales are expected to slow next month.
CBI director-general Richard Lambert said: 'As World Cup euphoria fades, so may sales, with retailers expecting sales growth to be moderate in August. This fits in with the broader outlook as consumers are under pressure.'