The rate of CPI inflation has fallen to 3.4% in February from 3.6% the previous month - a 15 month low.
The rate of RPI also fell last month from 3.9% to 3.7% and the underlying RPI rate of inflation fell to 3.8% in February, from 4% in January, the ONS said.
Lower electricity and gas bills, cheaper air fares and discounts on digital cameras helped pull the CPI rate lower, but a record January to February rise in alcohol prices, driven by spirits, held back further declines.
The drop comes as some economists warn that the overall rate of inflation may not pull back as quickly as previously thought amid resurgent oil prices, although the ONS said there was no evidence of this in February.
Despite the drop the figure is still less than the Bank of England target for inflation.
Howard Archer, Chief UK and European Economist at IHS global insight said there was concern inflation could be "stickier than had hoped" because of the price of oil: "While inflation should fall back further over the coming months, the concern is that it will prove stickier than had been hoped for due to current high oil prices.
"It had seemed very possible that consumer price inflation would be down to the Bank of England’s target level of 2.0% by the end of 2012 due to the waning impact of sharply rising oil, commodity and food prices in late/2010/early-2011, and by underlying price pressures being diluted by weak economic activity and elevated unemployment. However, this is currently looking increasingly questionable given current oil price levels and the possibility that they could go higher still or at least stay elevated for an extended period."
Azad Zangana, European Economist at Schroders said the drop in inflation had not met economists' expectations.
"Annual consumer price inflation (CPI) jumped fell from 3.6% in January to 3.4% in February – the lowest annual rate of inflation since November 2010 (3.3%). However, the consensus amongst Economists was for a fall to 3.3%, as the increase in prices between the two months 0.6%, was higher than expected," he said.