Long-Evans rat pups, 17-18 or 24 days of age, were trained with an eyeblink conditioning (EBC) procedure that has recently been used with adult rats. Pups received 3 sessions of delay conditioning in a single day, at about 4 hour intervals (100 trials/session). Trials involved pairings of an auditory conditioned stimulus (2.8 KHZ, 82 dB tone), and a periocular-shock unconditioned stimulus (US, 100msec, 2 mA), presented 280-msec apart. EBC was observed at both ages, but older pups learned much more rapidly. Subsequent experiments established that the effect is associative (Experiment 2), that age differences in EBC cannot be attributed to differences in the ability to respond or in sensitivity to the US (Experiment 3); and that EBC can be modulated by motivational state (Experiment 4). These results indicate that EBC can be studied in the developing rat. Further use of the preparation could help elucidate the relation between neural development and the ontogeny of learning.