The purpose of this study was to determine whether familiarity with a cue would enhance the ability of rats with hippocampus (HPC) damage to locate a cued hidden platform in the Morris water test. After preoperative training with the cue (n = 21) or handling only (n = 17), rats were given electrolytic bilateral HPC lesions or sham surgery for controls. All rats were then tested for 4 days, 6 trials per day, with the cue marking the platform location. Rats with HPC lesions familiar with the cue (FB) were significantly more efficient than rats with HPC lesions unfamiliar with the cue (UB) in swim time (M=10.31 ± 2.2 vs 46.72 ± 7.5 sec, p < .05) and in directional heading error (M = 31.98 ± 3.4 vs 57.92 ± 4.0 degrees, p < .05) on Day 1. These differences occurred across the 4 test days and were shown to be the result of an impairment in learning of the cue task in the UB groups rather than simply an effect of more practice with the cue by FB animals. No significant differences were found between FB animals and familiar controls.