Saudi Arabia's inflation climbed to an eight-month peak of 5.3 percent on an annual basis in September, official data showed on Sunday.
The rate was boosted by rises in the prices of miscellaneous products and services, according to the data from the Central Department of Statistics.
Analysts had expected consumer prices in the world's top oil exporter to gather momentum this year after the government pledged early in 2011 to spend an estimated $130bn, or nearly 30 percent of annual economic output, on housing, job creation and other measures to improve social welfare.
The largest Arab economy is seen expanding by 6.2 percent in 2011 following 4.2 percent growth in 2010, helped by robust crude prices and generous government spending, according to a Reuters poll of analysts last month.
Saudi inflation accelerated to 5.3 percent in 2010 from 5.1 percent in 2009, still below a record high of 9.9percent in the oil-boom year of 2008 but well above its long-term average of around 1 percent.
Saudi Arabia's central bank chief Muhammad al-Jasser told Reuters on Saturday that interest rate settings were appropriate at the moment with no signs of inflation coming from monetary impetus.
He also said in October that inflation levels were not worrying and would continue to decline.
Simon Williams, MENA chief economist, HSBC, Dubai, said: "External pressures might have had some effect but this is mostly about domestic demand. Public spending is rising faster than elsewhere and credit growth is recovering more strongly.
"We continue to look for an end-year reading of around 6 percent."