Output by local manufacturers last month fell by a seasonally adjusted 1.8 percent from a month earlier, Statistics Korea data showed, as the January reading was revised down to a 0.1 percent fall from a preliminary 0.1 percent rise.
The median forecast from a Reuters survey of 12 analysts tipped the February output to fall by 0.2 percent from January, with forecasts ranging widely from a 3.1 percent drop to a 4.1 percent gain.
February's industrial output rose 4.3 percent in annual terms, compared with a 4.1 percent rise tipped by the Reuters survey.
South Korea's manufacturing output closely mirrors its exports, as the country is home to some of the world's largest producers of cars, ships and smartphones. Overseas shipments in February rose 1.5 percent in annual terms.
February's service-sector output fell a seasonally adjusted 0.4 percent on monthly terms following a revised 0.7 percent rise in January.