A total of 5,400 new HIV cases were reported in 2006, down from 6,900 in 2005, newspapers said, quoting health ministry figures.
The deputy director of the ministry's disease control unit, Abdul Rasid Kasri, told the New Straits Times that he hoped the figure would fall even further to about 5,000 cases in 2007.
"In the past, 80 percent of Malaysians testing HIV positive were drug users. But lately, fewer cases were being diagnosed in this group," with unsafe sex accounting for more new infections, he said.
"This is probably due to the trend in drug usage. Designer drugs are taking over from intravenous drugs."
He said the number of cases involving women has risen in the last five years, from six percent to 20 percent.
Malaysia last year embarked on a five-year plan to curb the spread of HIV/AIDS, launching a pilot needle exchange programmes for drug addicts.