The US Missile Defense Agency (MDA) said a ground-based interceptor missile launched from Vandenberg Air Force Base in California hit a dummy armed missile in space that had been fired from Kodiak, Alaska.
The agency "successfully completed an important exercise and flight test involving the launch of an improved ground-based interceptor missile designed to protect the United States against a limited long-range ballistic missile attack," Air Force Lieutenant General Henry Obering, the agency's director, said in a statement.
The test initially had been scheduled Thursday but was postponed a day due to bad weather in Kodiak.
To downplay expectations, the US military warned in advance that the test was aimed primarily at determining whether the new ground-based interceptor could recognise its target, and not necessarily at interception itself.
The US missile defence system employs radar and satellites to detect enemy missile launches and guide interceptors to their targets.
The capability of the US missile defence system to function under a real attack remains a subject of controversy, with even President George W. Bush recently saying it would have a "reasonable chance" to intercept an incoming North Korean missile.
Seven opposition Democratic legislators, including Representative Ike Skelton, sent a letter to Defence Secretary Donald Rumsfeld on Tuesday voicing concern about the reliability of the system and calling for a test "in operationally realistic conditions."
The next test scheduled late this year or in early 2007 will have a principal goal of hitting the target.