More than 40 soldiers, sailors and airmen were sacked for taking drugs in 2010-11, Defence figures show.

The Army discharged 30 soldiers for returning positive drug tests while the Air Force discharged five and the Navy sacked eight sailors.

Cannabis was the most popular drug, but positive tests for ecstasy, steroids, cocaine and amphetamines were returned.

There were 24 positive tests for cannabis within the Army, nine for amphetamines and one for heroin. There were three positive tests for psychedelic drugs.

Within the Navy, cannabis was again the most popular illegal drug with 13 positive tests returned.

Another six were found to have taken steroids while three had taken cocaine.

There were 3,769 tests across the RAAF in 2010-11, with seven positive results returned. Five of those were for cannabis, one for ecstasy and one for methamphetamines.

In total there were 81 positive tests across Defence with some of those related to drink spiking, while other members remain on duty or administrative action against them is ongoing.

The figures, provided by Defence, did not specify if the tests were conducted on the battlefield or on domestic bases.

Random and targeted drug testing has been undertaken within Defence since 2005.

"The rate of positive tests in the Australian Defence Force is significantly lower than in the general Australian community, and has fallen by around 80 per cent since the testing regime was introduced," a spokesman for Defence Personnel Minister Warren Snowdon said.

"While any positive test results for prohibited substances are disappointing, it is heartening to see the rate of positive results is declining."

In 2009 the Defence Force denied reports some troops returning from Afghanistan were coming home addicted to drugs.

AAP