The discount chain, which floated in March last year, said its sales rose 10.2 per cent in the 13 weeks to 28 December, a slowdown on the 15 per cent reported in the first half.
It attributed this to the timing of new store openings but said it remained on track to open 60 stores in the UK and Ireland this year.
Shares fell 3.63 per cent to 350p last night. Jefferies analysts warned that Poundland sales could continue to slow if new openings cannibalise sales from existing stores and rival discounters step up their game.
Despite the slowdown, chief executive Jim McCarthy said it was on track to hit full-year forecasts after a record Christmas. Its trial stores in Spain have also performed well.