The index remained above 50, which indicates continued growth. But the pace of growth slowed from December, as the index dropped from 51.6 to 51.4.
The business activity measure came in shy of the 51.7 monthly average for 2013, HSBC said in a report produced by Markit Economics.
Manufacturing growth was "little changed" from December and only slightly below its historic, eight-year average, the report said, but the concentration of business activity shifted. "Slower expansion in China and Brazil, and falling output in Russia and Indonesia, were offset by stronger growth in India, Poland, Taiwan and Mexico," the report said.
Growth in services in the largest emerging markets -- Brazil, Russia, India and China -- declined. "India and Brazil both posted declines, while growth rates in China and Russia were weak," the report said.
"Although both the aggregate manufacturing and services PMI deteriorated in January, they remain in expansion territory," said Pablo Goldberg, global head of emerging markets research.
"Interestingly the future activity index shows a pick-up for manufacturing and a drop for services, suggesting expectations of an export-led recovery," he said in a statement.