That was the first time in a decade that HDFC Bank's net profit has fallen below 30 percent.
Net profit rose to 19.8 billion rupees in the quarter ended September 30 from about 15.6 billion rupees a year earlier, the bank said on Tuesday. Net interest income grew nearly 15 percent to 44.8 billion rupees.
According to Thomson Reuters I/B/E/S, analysts had expected HDFC Bank to post net profit of 19.8 billion rupees.
Asset quality at the third-biggest Indian lender behind State Bank of India and ICICI Bank worsened, with nonperforming loans as a percentage of total assets at 1.1 percent compared with 0.9 percent a year earlier.