Private-sector business gained momentum at the start of this year, building on moderate growth at the end of 2012.
Increases in output, new business and employment, combined with the slowing rate of operating costs, contributed to further gains in 2013, according to the Bank of Scotland's latest purchasing managers index (PMI).
The PMI is based on data compiled from monthly replies to questionnaires sent to purchasing executives in around 600 private manufacturing and service sector companies.
It measured an increase from 51.2 points in December to 52.3 in January - a seventh-month high for the index.
The score signals a moderate and accelerated expansion of private sector business activity, with growth remaining centred on the services sector.
Firms continued to add to their payroll numbers during January, raising employment levels for the seventh time in the past eight months.
Donald MacRae, chief economist at Bank of Scotland, said: "The Scottish economy gained momentum in January this year with the PMI reaching a seven-month high of 52.3.
"Both the level of new business and employment rose in the month but were concentrated in the service sector.
"The rate of decline in manufacturing output was modest and has eased since the previous month but export demand remains weak.
"This result suggests the Scottish economy not only started the year in growth mode but has maintained moderate growth throughout January 2013."