The news sent H&M's share price surging on Tuesday.
H&M had tumbled into a loss in its March-May quarter when, like many other non-essential retailers, lockdowns around the world forced it to close shops.
And while sales for the June-August quarter were still down 19 percent from last year to 50.9 billion Swedish kronor (4.9 billion euros, $5.8 billion), a move towards higher value collections, less discounting, and cost cutting helped it turn a profit, the company said in a preliminary earnings statement.
The preliminary pre-tax profit of approximately 2.0 billion kronor was much more than the 250 million expected by analysts, sending H&M shares climbing by more than 10 percent in morning trading in Stockholm.
The group is to publish its complete third quarter results on October 1st.