The iPhone 15 accounted for 3.5% of the global smartphone market, followed by the Pro Max, Pro and Galaxy A15 4G, according to a report by Counterpoint Research.
But in Vietnam, most retail chains report sluggish demand for this model.
At FPT Shop, the iPhone 15 did not even make it to the top 10 phone list in the third quarter.
Similar trends were seen at other retailers like CellphoneS and Di Dong Viet, where the Pro Max is among the top selling devices.
The Pro Max costs around VND30 million in Vietnam (US$1,180), compared to VND20 million for the iPhone 15.
Nguyen Lac Huy, a spokesperson for CellphoneS, said the Pro, which comes in a titanium case, offers great performance and is capable of running Apple Intelligence features.
For users with a lower budget, other options such as the iPhone 13 are more competitive than the iPhone 15, he added.
Globally, four of the 10 best-selling smartphones are made by Apple, with Samsung accounting for five and Xiaomi for the remaining one.