The census was planned to take place this summer to track the population and humanitarian needs, but Afghan officials have halted the project, citing security concerns.
Abdul Sakhri, vice-president of the central statistics office, said: "The cabinet had no choice than to postpone the project because it was deemed too risky. Sadly, it hits where help is needed the most - in the war-torn southern regions. We were planning to track each village's humanitarian needs - for instance water supply or educational requirements - as well as the population. It's a huge missed opportunity," he said.
The census would also have enabled the country's electoral record to be more accurate ahead of next year's planned parliamentary elections, he said.
The cancellation coincides with this week's Paris donor conference, which is expected to seek billions of dollars in aid for Afghanistan. The project has been pushed back to 2010. Aid agencies will have to continue to rely on the data from the previous 1979 census.
Many in Kabul predicted the fall of the project. Ghulam Jelani, development manager at Aims, the UN-backed information management service, said: "The project was a challenging one. Culturally, people are not comfortable talking about their family with a stranger."
A pilot census took place in 2002. So far $31m (£15m) has been spent out of the $60m allocated for the UN-funded project. The country's current population estimates vary from 24 million to 33 million people, depending on different sources.
© 2008 The Guardian