Launching Zimbabwe's national census on Wednesday, President Robert Mugabe said he hoped the once-a-decade count would measure the extent to which AIDS was affecting the people of Zimbabwe.
Mugabe said he was disappointed by 2002 census results, which showed the southern African nation's growth had slowed dramatically because of the disease.
"The country's population has been decimated by the pandemic we all know, HIV and AIDS," Mugabe said.
According to the 2002 count, Zimbabwe's population was 11.6 million, up 1.2 million from a decade earlier.
But the growth rate slowed as AIDS erupted across the region.
After peaking at 3.98 percent in 1983, the annual population growth rate began a steady slide, bottoming out in 2007, when the population is thought to have shrunk by 0.38 percent, according to World Bank data.
Though about 13 percent of the population is HIV positive, Zimbabwe has emerged as something of an AIDS success, with new HIV infections down 50 percent between 1997 and 2007, a study last year found.
Officials are encouraging male circumcision because some research has shown the procedure can reduce HIV transmission rates.
Zimbabwe has also seen an exodus of people fleeing political and economic turmoil over the last decade, with some estimates suggesting three million people have left.
The census will cost about $40 million, with donors chipping in $12.6 million, the finance ministry said.\