Less than 2% of all Android devices are running Google's latest operating system - almost three months after it was launched.
Phone manufacturers have long been criticised for not bringing Android updates to their devices in a timely manner.
Android 4.1 Jelly Bean was unveiled in July, but is installed on 1.8% of Android devices, according to Google's stats.
More than 55% are still running Android 2.3 Gingerbread, just under two years after its launch.
The stats are based on the devices which accessed Google's Play store over the last 14 days.
Several key Android devices, including the Samsung Galaxy SIII, are yet to receive upgrades to Jelly Bean.
Samsung has promised to roll out Jelly Bean to the UK at the start of October, and availability is expected imminently.
By contrast, Apple's latest upgrade (iOS 6) has already been installed on as many as 35% of iPhones, iPads and iPod Touches just a few weeks after launch.
Apple said that more than 100 million people had already upgraded as of seven days ago.
That comes despite the heavy criticism Apple has endured over the quality of its new Maps app, included in iOS.