The aim of the study was to examine the relationship between working memory and source memory of older adult eye witness and the accuracy of their testimony. The effects of age and other individual-demographic factors on eyewitness testimony were also investigated. Fifty participants allocated into two age-groups (25 old adults and 25 younger adults) were examined. Participants were administered a source memory task, a working memory task, and an eyewitness simulator task. Only working memory was associated directly and positively with the accuracy of eyewitness testimony, while age-group, physical exercise and educational level were found to affect eyewitness testimony indirectly, via working memory capacity. Older adults reported higher feeling of confidence for the accuracy of their testimony, compared to younger adults.