Vendors shipped 144.9 million smartphones during the first three months of 2012 compared to 101.7 million in the same period last year, the market research company said.
Samsung sold 42.2 million smartphones, which is a new record, while Apple sold 35.1 million during the first quarter. That means about every second smartphone sold across the world came from either Samsung or Apple.
Since Samsung doesn't report unit numbers, IDC and its competitors have to estimate how many devices the company sells.
Last week, Strategy Analytics said Samsung shipped 44.5 million smartphones in the first quarter, while another research firm IHS iSuppli said the company only shipped 32 million, giving it the second place in the smartphone market.
The race between Apple and Samsung remained tight during the quarter, according to IDC. Propelling Samsung forward was the continued expansion of its Galaxy portfolio in nearly all directions, while the launch of the iPhone 4S in China helped boost Apple sales, it said.
Apart from shipments by Samsung and Apple, the numbers weren't very pretty during the first quarter.
Nokia came in third by selling 11.9 million units, but the company's market share dropped by 50.8%, according to IDC.
Symbian phone shipments declined precipitously as demand dropped in important emerging markets, including China. The company's current woes make a speedy transition to products powered by the Windows Phone operating system critical, IDC said.
Research In Motion (RIM) saw its unit sales drop by 29.7% reaching levels not seen since 2009, according to IDC. But 9.7 million units was still enough to make it the fourth largest vendor.
Like Nokia, RIM is a company in transition. Smartphones running on its new platform, BlackBerry 10, will be released later this year. Until then, results like these may be a sign of things to come, according to IDC.
HTC, which came in fifth place, sold 6.9 million smartphones during the first three months of 2012, compared to 9 million during the same period in 2011, according to IDC's data.
HTC continued to struggle in the U.S. market, and the company is now staking its future success in large part on its One X and One S products.
"The smartphone market is a two-horse race at moment, and we don't see that changing this year," said Francisco Jeronimo, research manager at IDC.
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