CyberMedia Research (CMR), a computer and electronic market research firm said 35 of percent of handsets sold in 2011 could have more than one network connected (multi-subscriber identity module).
Around 5.4 percent or 110,000 units out of 2.03 million were smart phones.
The firm does not count hand carried or grey market and only tracks units shipped by original equipment manufacturers to retailers for sale in Sri Lanka.
By end 2011, Sri Lanka, a country of 20 million people had 18.3 million mobile subscribers which grew 6.1 percent from a year earlier. Amid competition, price conscious mobile users were buying more than one package.
The CRM said its market review showed than Nokia had a 46 percent share of phone shipments, Samsung 22 percent and Micromax 16 percent.
In the multi-SIM segment the Micromax brand has a 37.3 percent share, Nokia 24.6 percent and Samsung 15.9 percent, CRM said.
Around 320,000 third generation (3G) phones were shipped to Sri Lanka in 2011 with Nokia having a 53.2 percent share, Samsung 25.6 percent and Sony Ericsson 7.7 percent.
"With the spread of 3G services to all major cities Sri Lanka consumers would look to acquire and use more feature rich mobile handsets, thus fueling greater demand for higher generation air interface devices," Naveen Mishra, lead telecom analyst at CMR said in a statement.
"This is an opportunity that vendors and service providers can exploit by bringing to market attractive value-for-money device-plus-service packages."
Out of 110,000 smartphones shipped, Samsung had a 27.6 percent share, Nokia 25.4 percent and HTC 11.4 percent.
Android was the most popular operating system with a 49.9 percent share.
Smartphone models on offer in 2012 are also likely to go up with operators in the island focusing more on data revenues, CRM analyst Tarun Pathak said.
Vendors Could benefit from producing more handsets that supported the Sinhala language, spoken by a majority of the population as well as those which were moisture and water resistant, he said.