The fast-growing chain, which sells everything from bedding to barbecues, said group sales jumped by 31.9 per cent to £367m in the first quarter to 28 June.
UK sales grew by 22.6 per cent to £341.2m, with sales at stores open more than a year up by six per cent compared with the same time last year, when they rose 7.3 per cent.
Chief executive Simon Arora said the first quarter “has been a strong one”, with trading boosted by seven net new store openings across the UK.
“Our like-for-like performance was driven by our strong product offering, growth in the average customer transaction value and the late Easter,” he added.
The business was founded in 1978 by shopkeeper Malcolm Billington in the seaside resort of Blackpool.
Arora and his brother Bobby took control of the chain in 2005 and have grown its from a loss-making retailer with 20 stores into a force on the high street with over 370 stores.
B&M’s £2.7bn flotation in June delivered a windfall payout of around £1bn for the Arora brothers, the chain’s private equity owners Clayton Dubilier & Rice, and its chairman, the former Tesco boss Sir Terry Leahy.
It was one of the few retail floats to see shares rise above its initial offer price of 270p on its first day. Shares closed up slightly at 278.5p yesterday.
Arora said at the time of the float that it aims to expand the chain at a rate of around 40 new shops a year. He has said two-thirds of the British population do not have easy access to B&M, and there is room for around 850 stores across the UK.
In March, the company bought a majority stake in German discount retailer JA Woll Handels in its first move outside the UK.