The site now boasts 238 million users, a 37 per cent increase from a year ago and a 9 per cent increase from the first quarter.
LinkedIn's revenues have beat expectations for nine consecutive quarters while other social media firms have stumbled badly since going public.
Still, the professional social network faces the same challenges as its competitors, and Chief Executive Jeff Weiner has previously signaled that LinkedIn's new mobile products could take months to gain traction.
Those concerns lingered when the company on Thursday provided a lower-than-expected forecast for the third quarter, which tempered investor enthusiasm.
The San Francisco company projected sales of between $367 and $373 million for the third quarter but also raised its full-year revenue guidance to between $1.455 billion and $1.475 billion.
Excluding certain items, LinkedIn reported earnings of 38 cent per share for the quarter.
The company's shares rose 7 per cent to a record $228.50 after the bell.
The social network makes much of its money by selling access to its members' resumes to corporate recruiters.
But as the social network has approached a saturation point among white-collar workers in the United States, the CEO has pursued growth by turning LinkedIn into a popular mobile app and highly trafficked website rather than a mere resume repository.
In recent quarters, he has introduced blog posts by luminaries like Bill Gates in an attempt to draw Web traffic - and with that, advertising revenue.
Non-GAAP net income for the second quarter was $44.5 million, compared to $18.1 million for the second quarter of 2012.
LinkedIn shares have roughly doubled in the past year.