Gono was responsible for putting the bank's printing press into overdrive to keep pace with hyper-inflation.
At the height of the southern African country's decade-long economic crisis, Zimbabweans were plagued by acute shortages of foreign currency and basic goods, while inflation spiked to 500 billion percent in 2008.
By that time, funding for most government departments was coming via the central bank and official government records show that it accumulated more than $500 million in debts during Gono's tenure.
Some companies have alleged the central bank used foreign currency from accounts of companies and non-governmental organisations held with the central bank.
During one court hearing earlier this month, a central bank lawyer accepted liability and said the money would be returned, but gave no dates. The government has agreed to take over all central bank debts.
"Like any mortal being, I was not perfect. I was not and am not a saint," Gono said in a farewell statement.
Gono, a former personal banker of veteran President Robert Mugabe, is remembered by many for his favourite phrase "failure is not an option".
He said a new governor was expected to be announced after next February.
Gono's influence ended suddenly in 2009 when Mugabe and the opposition Movement for Democratic Change party formed a unity government and ditched the Zimbabwe dollar in favour of the U.S. currency, which rendered Gono's position largely ceremonial.