The company, which caters for fashionable 16- to 34-year-olds, reported revenues of £339.7m, up 52% from £223m, in the year ending 31 March 2011.
Pre-tax profits fell 23% from £20.3m to £15.7m, but when exceptional items – the cost of shifting its warehouse operations from Hemel Hempstead to Barnsley – were taken out profits were up 41% from £20.3m to £28.6m.
The group upped its investment in marketing by 54% from £9.25m to £14.3m in the period, in a bid to drive up customer awareness of the brand, both nationally and internationally.
In the period, Asos has put an emphasis on overseas expansion and launched online operations in the US, France and Germany. This year it plans to launch in Australia and Spain.
Nick Robertson, chief executive, said: "Our international expansion programme remains firmly on track with international retail sales up 142% on last year."
International sales now account for 43% of total retail sales, compared to 28% the year before.
Robertson said the new warehouse would be up-and-running by June this year.
Robertson was bullish about the company's performance. He said: "I am pleased to report another successful year for Asos, with retail sales up 58% to £324.1m and profit up 41% to £28.6m. Our international expansion programme remains firmly on track with international retails sales up 142% on last year."
Earlier this year, Asos reported that its international sales had overtaken UK sales for the first time.