The survey of 4,245 workers across the UK revealed that just one in three employees accesses Twitter, Facebook, LinkedIn or other social networking sites while at work.
But for some professions, social networks have become a staple of the working day. Almost half of marketing and PR professionals tap into the social sphere every day, compared to just a quarter of finance workers.
And when it comes to following Twitter or updating a Facebook status, mobile takes the lead: 60% of UK employees opt to use their phone over a work computer.
The research also revealed that one in four businesses has banned employees from browsing social networking sites during work hours. However, 35% of employers give full access and, while the remaining 40% do allow access, it is almost always permitted for business purposes only.
Martin Warnes, MD of reed.co.uk, said: "In spite of the phenomenal popularity of Facebook and Twitter, the majority of UK workers would rather steer clear while they are at work, with many seeing them as an unwelcome distraction or a risk to their privacy.
"But social networks aren't just about liking and poking, they have an increasingly important role in business and in career development. Used in the right way, social networks offer a powerful platform for engaging with new customers, strengthening client relationships and gathering information.
"For many, social networking is a way of life, and smartphones allow us to stay up-to-date no matter where we are and what we're doing. So to avoid a situation where employees are surreptitiously accessing Facebook and Google + under their desks, employers should engage with their staff to determine an appropriate policy for use," said Warnes.