Information and procedures that have been overlearned during a lifetime form a body of 'crystallized' intelligence that is relatively unaffected by ageing. Thus in spite of marked decrements in their 'fluid' memory abilities it is possible that older people may retain knowledge about the limitations and characteristics of their own memory ('metamemory'). To test whether efficiency of metamemory is, indeed, independent of age-related decline in fluid intelligence, 320 people aged from 50 to 79 years were asked to predict their probable performance on four simple memory tasks which had been carefully explained to them. They then experienced the tasks and their predictions were compared with their actual performances. Actual task performance was modestly predicted by chronological age and by AH 4 and Mill Hill IQ test scores but not by subjective self-ratings of everyday memory and cognitive efficiency (the Broadbent CFQ, and the Sunderland & Harris MQ). The data suggest that absolute levels of prediction of performance were associated with self-confidence and were best predicted by scores on the Beck depression scale and by fluid IQ test scores. There was also evidence that individuals with higher test scores gave more accurate as well as more optimistic predictions of their own abilities. Taken together these results suggest that the accuracy of individuals' assessments of their own abilities does alter with age-related changes in fluid IQ, but probably more radically by age-related changes in self-regard and in life-style.