For the first time, the worldwide smartwatch market saw an annual decline of 32%, according to preliminary data from the International Data Corporation.
Smartwatch vendors shipped 3.5m units in the second quarter of 2016, which was down substantially from the 5.1m shipped a year ago.
Apple held the top rank by shipping 1.6m watches.
However, it was the only retailer among the top five to experience an annual decline in shipments.
For Apple, the year-over-year comparison is to the initial launch quarter of the Apple Watch, which is in many ways the same product offered in the most recent quarter with price reductions.