ANZ chief executive officer Shayne Elliott said some customers were struggling as rising rates pushed up borrowing costs but most were "managing their way through" the current financial pressures.
Higher interest rates have been inflating mortgage repayments, with the high cost of living also eating into household budgets.
Addressing a parliamentary hearing on Wednesday, Mr Elliott said only $6 of every $1000 in its Australian home loans portfolio was overdue by more than 90 days.
"This is better than before the pandemic," he said.
The bank boss offered three explanations for the display of resilience: the strong levels of employment, big savings buffers and robust credit standards that have kept lending responsible.
But he said the figures were aggregate numbers and some Australian households were struggling, with the bank observing a "modest increase" in the number of customers asking for help.
"We will continue to watch how our customers are going and support them when we can," he said.
The bank's CEO also outlined his position on the three per cent serviceability buffer, saying lowering lending standards would help few customers at the bank.
Stress-testing customers' ability to make repayments at three per cent above the market interest rate is designed to protect a borrower if economic conditions or their financial circumstances change.
But there has been concern that the rules are locking customers in "mortgage prison", when borrowers cannot meet the stress-testing requirements to refinance to a better deal.
Mr Elliott said there would always be exceptions and some individuals were suitable for lower standards.
The bank's position is that the Australian Prudential Regulation Authority's three per cent buffer is appropriate, but it is open to the standard being reviewed at a later date.
NAB chief Ross McEwan will also appear at the parliamentary economics committee hearing in Canberra on Wednesday.
He will be followed by the bosses of Westpac and the Commonwealth Bank on Thursday.
Committee chair Daniel Mulino said the two-day hearing was a timely opportunity to put the spotlight on the four banks, which control 80 per cent of the Australian market.
"Australian households and small businesses depend on these banks for general banking, mortgages and business loans," he said.
"It is crucial our banks are resilient but also competitive."