In the first quarter, PC sales fell 1.1 percent around the world to 84.3 million units, with a 6.1 percent drop in U.S. sales, reported Gartner, a computer industry research firm.
USA Today Friday quoted Gartner analyst Mikako Kitagawa as saying "the hype" around tablets was responsible for the shift in PC sales, which forecasters had expected would rise by 3 percent.
Manufacturer Hewlett-Packard saw its PC sales drop 3.4 percent in the quarter while Dell's PC sales slipped 2.2 percent.
PC maker Acer saw its sales tumble 12.2 percent, the newspaper said, due to its reliance on netbooks.
Perhaps ironically, Apple, which is expected to ship 48 million iPads this year, saw its PC sales rise 18.9 percent in the first quarter.
"There are a lot of uncertainties in the market," Kitagawa said.
"The tablet and consumer electronics devices' effect on PCs will depend on how the tablet market and smartphone continue to evolve going forward."