Serial reversals of a spatial discrimination were trained in rats under automaintenance conditions, in which food reward occurred regardless of responding. The automaintained reversal learning was compared to instrumental reversal learning in other rats trained under a similar procedure which required responding for reward. In the automaintenance (AU) procedure, rats received food after every retraction of a 'positive' response lever (S(sup +); retraction of a second, neutral lever S(Sup 0) was not paired with food delivery. A second group of rats was trained on a similar instrumental schedule, in whi ch at least one response to the S(sup +) was required for food delivery. Response rates in the instrumental (IN) group were approximately double those of the AU group. However, ratios of S(sup +) to S(sup 0) response rates were similar to those of the AU group, and the serial reversal curves generated were qualitatively similar. Thus rats can show improvement across serial reversals of a spatial discrimination based entirely on pairings of stimulus events (automaintenance), in a manner similar to that observed in instrumental procedures, in which reward is contingent upon correct responding.