Exports rose 26.9% from a year earlier to $39.55 billion last month, the Ministry of Finance said on Tuesday, the highest monthly figure on record.
Analysts in a Reuters poll had forecast a rise of 23.55% for August, compared with a 34.7% increase in July.
The ministry attributed the growth to "robust" demand for chips, a shortage of which has shuttered car plants globally and is affecting consumer electronics and the gradual re-opening of economies around the world, even with the COVID-19 pandemic not abating in many countries.
Electronics exports hit a record high in August at $15.22 billion, with semiconductor exports growing 21.7% from a year earlier.
Firms such as Taiwan Semiconductor Manufacturing Co Ltd (TSMC) are major suppliers to Apple Inc and other global tech giants, as well as providers of chips for auto companies and lower-end consumer electronics.
The ministry said it was "cautiously optimistic" about the outlook for exports in the second half, helped by strong demand for the island's advanced chips as well as the year-end holiday season, traditionally a busy time for Taiwan's tech firms.
However, it warned of risks ahead from a rise in COVID-19 variants globally, and tight international supply chains.
August exports to China, Taiwan's largest trading partner, jumped an annual 16.1% to $16.77 billion, while exports to the United States grew 28.9% on year, both setting record highs by value.
Imports leapt 46.3%, against economists' expectations for a 29.4% rise and an increase of 41% in July.
Taiwan could see September exports increase in the range of 23% to 27% compared with a year earlier, with the figures affected by fewer working days due to the long weekend Mid-Autumn Festival holiday that month, the ministry added.
In China, Taiwan's largest trading partner, exports also unexpectedly grew at a faster pace in August thanks to solid global demand.
(Reporting by Liang-sa Loh and Ben Blanchard. Editing by Gerry Doyle)