The number of mobile phone users in East Timor stood at more than 622,000 at the end of last year, according to official data published on Tuesday.
The total grew by 375 percent in just 18 months, reported Portuguese news agency Lusa.
The majority of mobile users in East Timor relied on pre-paid cards to cover their costs.
The mobile phone penetration rate in the country is however still low by international standards. There is just one mobile for every 1.9 persons living in East Timor.
The number of people subscribing to mobile data services also remained low by the end of last year, at less than 3,500, according to the Lusa report.