The dock features a USB input and a headphone jack, allowing users to charge their tablet or connect it to a speaker.
Asus, who first unveiled the accessory at CES earlier this month, has assured customers that fresh stock is on the way.
"It's sold out already, but more stock should be landing shortly," a company spokesperson told Pocketlint.
The Google-branded Nexus 7 was released last summer as the launch vehicle for the Android Jelly Bean operating system. New 32GB and 3G models were added to the line in October 2012.
The Nexus 7 docking station is priced at £24.99.