This study investigated the mechanisms behind episodic autobiographical memory (EAM) development in school-age children. Thirty children (6-11years) performed a novel EAM test. We computed one index of episodicity via autonoetic consciousness and two indices of retrieval spontaneity (overall and EAM-specific) for a recent period (previous school year) and a more remote one (preschool years). Executive functions, and episodic and personal semantic memory were assessed. Results showed that recent autobiographical memories (AMs) were mainly episodic, unlike remote ones. An age-related increase in the indices of episodicity and specific spontaneity for recent AMs was mainly mediated by an age-related increase in the efficiency of the three cognitive abilities. Remote AMs varied only slightly with age (overall spontaneity), reflecting improvements in semantic abilities. Thus, EAM development in school-age children is essentially bound up with the increasing efficiency of cognitive abilities. Results are discussed in the light of models of childhood amnesia.