Test purchases in 23 cantons in 2010 showed that underage people were able to buy alcohol 26.8 percent of the time, according to the Swiss Alcohol Board, the lowest rate since testing began in 2000.
Eleven years ago, young, undercover buyers successfully purchased alcohol 83.5 percent of the time.
From 2009 to 2010, the number of successful test purchases dropped by 5.8 percent.
Shops and restaurants now are in the habit of checking identification before selling liquor, wine or beer, asking for some kind of ID 75 percent of the time.
The easiest places for underage drinkers to get hold of alcohol were cafés and restaurants, where buyers successfully walked away with liquor in hand 32.5 percent of the time. At gas stations, 22.6 percent of the test buyers were able to complete their alcohol purchases.
In 2010, the Swiss Alcohol Board conducted 4,920 tests in which people were sent into businesses to try to buy alcoholic products that they could not legally purchase. The board said the tests were helping curb alcohol sales to minors, although it said underage buying was still a problem.
All in all, some 15,000 tests were carried out between 2000 and 2010.
Swiss law says beer and wine cannot be sold to people under 16 years of age and liquor sales are prohibited to young people under 18.