The effects of within- versus between-languages (English-French) study and test on rates of bilingual children's and adults' true and false memories were examined. Children aged 6 through 12 and university-aged adults participated in a standard Deese-Roediger-McDermott false memory task using free recall and recognition. Recall results showed that: (1) both true and false memories increased with age, (2) true recall was higher in within- than between-languages conditions for all ages, and (3) there were fewer false memories in between-languages conditions than within-language conditions for the youngest children, no differences for the 8 and 12 years old, and by adulthood, there were more false memories in between-languages than within-language conditions. Recognition results showed that regardless of age, false recognition rates tended to be higher in between-languages than within-language conditions. These findings are discussed in the context of models of false memory development.