The deadly H5N1 strain of bird flu has been found close to the Pakistani capital, Islamabad.
Experts fear the virus could mutate
All the chickens in the infected flock died from the flu or were slaughtered, officials say. "We believe it is an isolated case," a spokesman said.
Last March H5N1 was found in north-west Pakistan, India and Afghanistan.
The H5N1 virus can cause illness and death in humans, but scientists say the chances of being infected are extremely low.
In the UK, nearly 160,000 turkeys have been culled in recent days at a farm in the south-east of England after bird flu was discovered there.
Mohammad Afzal of Pakistan's Ministry of Agriculture said the latest outbreak in the country had been found in chickens in Rawalpindi.
"They tested positive for the H5N1 strain," he told the Reuters news agency.
"It has been contained and there is no danger of the spread of this virus because there are no poultry farms near this house."
The H5N1 virus does not at present pose a large-scale threat to humans, as it cannot pass easily from one person to another.
However, experts fear the virus could mutate to gain this ability, and in its new form trigger a flu pandemic, potentially putting millions of human lives at risk.