This study investigated how visitors' psychological and behavioural factors, identified in the literature, shaped their vivid long-term memories of their experiences of the Japan World Exposition, Osaka, 1970 (Expo '70) as a context. In this study, 112 memory episodes were identified from the long-term memories of 48 participants; they were rated in terms of their memory vividness and on a set of factors including affect, agenda fulfilment, intentionality, and rehearsal. The influence of these factors on the vividness of episodic and/or autobiographic memories of experiences that occurred 34 years ago was examined in two stages. First, the relationship between memory vividness and individual factors was investigated separately. Second, the relationship between memory vividness and all factors was examined through a multiple regression analysis, and the relative importance of these factors on memory vividness identified. Stage one analysis showed that all factors except intentionality were related to memory vividness in individual analyses, and curvilinear relationships between memory vividness and the factors found. Stage two analysis, in which all factors were included in a multiple regression analysis, found that rehearsal was positively related to memory vividness and all other factors not significant in the presence of rehearsal.