Toyota Motor Corp.'s U.S. division said its August sales increased 22.8 percent compared with August 2012.
The automaker reported August sales of 231,537 units.
"The auto industry continues to be a bright spot in the economic recovery," said Bill Fay, Toyota division group vice president and general manager.
"August capped a great summer for new-vehicle sales, and it was Toyota's best month in more than five years."
Sales of Toyota's bread-and-butter Camry midsize sedan jumped nearly 22 percent to 44,713 units.
The redesigned Avalon full-size sedan posted a 254 percent year-over-year sales gain to 6,241 units, marking its sixth consecutive month of triple-digit gains.
Sales of the Prius hybrid were up nearly 30 percent to 27,358 units, marking its best August. Toyota's commands 60 percent of the U.S. hybrid market, according to Toyota Motor Sales USA Inc.