Rats trained on a series of 16 novel 2-odor discrimination tasks using a 10-s intertrial interval (ITI) rapidly improved in performance and made only 0-3 errors by the end of the test series. They were then tested on other novel pairs of odors, but with a 10- and a 30-min interval between trials. There was no decrement in performance accuracy in the longer ITI tests and, in most cases, criterion performance was achieved after making zero or 1 error after the first (information) trial. These results demonstrate that rats have the capacity to remember for at least 30 min whether a single brief presentation of a novel odor was followed by a reward.