The company, based in Vancouver, British Columbia, reported a net profit of $503,000, or 3 cents per share, on revenue of $20 million. That compares with a net loss of $3.9 million, or 24 cents per share, on revenue of $12.9 million, a year ago.
Analysts surveyed by Thomson First Call expected a loss of 2 cents per share.
Sierra's economic health often mirrors how well wireless Web subscriptions are selling in the United States. The company's modems are available from most U.S. cell phone service carriers that sell wireless Web access.
Chief Executive David Sutcliffe told analysts during a conference call that the number of modems sold in the quarter was surprising, and that the company experienced a backlog for some orders.
"The quarter started very well for us... and it kept on going well for us," Sutcliffe told analysts.