This could be the big-box retailer's latest move to take its e-commerce business to the next level.
Bloomberg first reported the news Friday, while the patent was first submitted in February.
The machine, similar to a blimp, could fly as high as 1,000 feet, the application says, and it would be operated either autonomously or remotely by a human pilot.
The patent describes, "Gas-filled carrier aircrafts and methods of dispersing unmanned aircraft systems in delivering products."
It goes on to say: "In a modern retail environment, there is a need to improve the customer service and/or convenience for the customer. One aspect of customer service is the availability of products. The availability of products is dependent in part on the distribution of products. There are numerous ways to distribute and deliver products. Getting the product to a delivery location, however, can cause undesirable delays, can add cost and reduce revenue."
A representative from Wal-Mart didn't immediately respond to CNBC's request for additional comment.
The two companies have been neck and neck — Wal-Mart growing its digital presence, and Amazon beefing up its real estate portfolio in planning to acquire grocery chain Whole Foods.
In October, Wal-Mart filed for another patent that tread on Amazon's turf, according to data provider CB Insights. This time, it was for a system similar to the internet giant's Dash buttons, which reorder everyday goods seamlessly in one click.
Wal-Mart reported second-quarter earnings on Thursday, revealing that its digital sales climbed 60 percent for the period. After the big-box retailer acquired Jet.com last September, it brought on the website's founder, Marc Lore, to lead Wal-Mart's e-commerce division.
A floating warehouse would allow Wal-Mart or Amazon to serve a wider distribution area than their current real estate allows. Now, the race is on to see which company can make the technology work before the other.