Mondal, who joined the bank in April 2019 from smaller rival Yes Bank and is widely credited with building HDFC Bank's highly successful retail franchise, was leading the retail segment at Axis Bank.
"It is an unanticipated but unavoidable development owing to some personal compulsions," Mondal was quoted as saying in a bank statement.
Sources within the bank said a search process to find Mondal's replacement is on and an internal candidate is most likely to succeed him.
The bank's retail assets grew 24 per cent in 2019-20 as against the overall growth of 15 per cent, and accounted for 53 per cent of the bank's loan book.
It also delivered 64 per cent of the overall fees, while the share of the low cost current and saving account balances delivered by the retail network stood at 39 per cent on a quarterly average basis.
Mondal was handpicked by the bank's chief executive and managing director Amitabh Chaudhry as part of the leadership transformation at the lender.
He succeeded Rajiv Anand, who was made the executive director for corporate or wholesale banking.
Mondal's exit comes within months of the bank losing its chief financial officer Jairam Sridharan, who moved on to join as the chief executive of Piramal Enterprises' consumer finance business.
There have also been reports of massive staff replacements at the lender under Chaudhry.
In the statement, Mondal said Axis has a strong franchise and he will "admire" the business as it continues to grow in the years to come.
Rajesh Dahiya, the bank's executive director for corporate centre said Mondal made "significant contributions" during his tenure, and added that the lender has a "strong leadership bench". AA RVK