About 65 percent of the country's murders resulted from arguments fuelled by substance abuse, Police Minister Nathi Mthethwa announced on Thursday.
Unveiling the 2011/12 crime statistics, Mthethwa said the country's murder rate had dropped by 3.1 percent since the previous reporting period.
"Murder is one of the most reliable trends of crime statistics," Mthethwa said.
In 2004/5 more than 18,000 people were murdered. Less than 16,000 murders were reported in 2011/12.
"This translates to a 27.6 percent reduction in murders over an eight year period," said Mthethwa.
He said research had shown that most murders were committed after an interpersonal argument, stimulated by heavy drinking and drug abuse.
Murder is one of seven categories grouped together as contact crimes.
The other categories are attempted murder, sexual offences, assault with the intent to do grievous bodily harm, common assault, aggravated robbery and common robbery.
"The crimes in question account for 29,9 percent of South Africa's serious crimes; such crimes involve physical contact (usually violent and coercive in nature) between perpetrators and their victims."
All provinces except the Free State, Limpopo and the Western Cape experienced a decrease in contact crimes.
"In the 2010/11 financial year, contact crime decreased by 6.9 percent and for the financial year under review, we recorded a decrease in 3.5 percent." - Sapa