Abstract Memory (digit span) and clinical personality measures (EPQ) were recorded from 37 caisson workers. These measures were correlated with their length of working experience in caissons and the maximum pressure under which they worked. No significant relationship was found between memory performance and personality measure for either caisson experience or maximum pressure (all p > 0.05). Further analysis, however, revealed a significant impairment in memory performance (forward digit span) for those workers with a recorded history of decompression illness (n=9, p<0.05) compared with firstly, caisson workers without a history of decompression illness (n=28); secondly, a control group of non-caisson workers (n=182, p<0.05); and thirdly, a control group matched with the decompression illness group on age and level of formal education (n=9, p<0.05). There was no difference between the groups on personality measures. The non-decompression illness group and control groups showed no difference in memory performance. These results are consistent with recent findings by the authors of memory performance amongst commercial divers who have suffered decompression sickness. Keywords: Caisson Workers, Memory, Digit span, Personality, EPQ, Decompression illness.