"My tenure ends Nov 29, 2013. On that day I will retire. May the almighty allah help and guide us all," Xinhua reported quoting Gen. Kayani as saying in a statement.
The announcement came amid media reports that Gen. Kayani is likely either to get extension or a new defence post. Some reports also said that he is likely to be appointed as Pakistan ambassador to the US.
The army chief, however, referred to the debate in the media about his current responsibilities and likely future plans as "all sorts of rumours and speculations".
Institutions and tradition stronger than individuals, he says.
"The subject of being entrusted with new duties has also come up in several reports. I am grateful to the political leadership and the nation for reposing their trust in me and Pakistan Army at this important juncture of our national history," the army chief said in the statement issued by the army's Inter-Services Public Relations.
"It is time for others to carry forward the mission of making Pakistan a truly democratic, prosperous and peaceful country that embodies the finest dreams our founding fathers had envisaged for us."
"However, I share the general opinion that institutions and traditions are stronger than individuals and must take precedence," he added.