Grocery store food prices in the Washington area declined for the first time in five years in 1981 in sharp contrast to the year before, when they climbed 14.4 percent.

Figures released yesterday by the Bureau of Labor Statistics underscored the relief some shoppers have felt at the checkout counter.

During the last month of 1981, grocery prices in the Washington area rose 0.2 percent, the BLS reported yesterday. From December 1980 to December 1981, prices in the Washington region declined 0.2 percent.

Nationally, prices for food at home increased 3 percent. The Washington area fared better than the nation in part because supermarket price wars in the spring and summer combined with other factors to hold prices down, according to spokesmen for the area's dominant supermarket chains, Giant Food Inc. and Safeway Stores Inc.

According to BLS economist Jesse Thomas, price decreases for beef, poultry, eggs and dairy products contributed to grocery price relief here. Thomas said that retailers' ability to control their costs also helped.

The sharpest declines during the year came when prices fell 2.7 percent in April and 2.4 percent in May. The biggest increases were 2 percent in both August and September.

The price wars started in April when Giant stopped marking prices on individual items. The grocery chain coupled the change with massive price cuts to water down consumer resistance. Safeway soon followed suit, and prices stayed relatively low for the summer.

In August, as losses began to mount, the so-called war approached a truce and prices moved up. For instance, the cost of a gallon of regular milk rose from a low of $1.69 in June to $1.89.

"A big factor here was the price war. It certainly brought prices down," said Ernie Moore, a spokesman for Safeway. "Prices have increased moderately since then, but they have not gotten back to where they were last December."

"The chief contributing factor in the Washington area was the price war," said Barry Scher of Giant.

Nationally, large meat supplies and an ideal summer growing season helped moderate price rises, said U.S. Department of Agriculture economist Ralph Parlett. Besides large supplies of red meat, "The sluggish economy has prevented increases, as demand has been off," he said.

The outlook for 1982 is for more moderate price increases, according to the USDA. The freeze that has swept the country will depress prices of fresh vegetables for approximately six weeks, he said. "But they will be able to replant and get going again because the freeze was early," he added.

Scher and Moore said that because the freeze wiped out fresh vegetables in Florida, where the chains normally buy, added transportation costs for shipping vegetables from the South and the West are increasing prices.