The dentate gyrus (DG) plays a key role in memory encoding and retrieval, facilitating discrimination of the environmental inputs by separating them into non-overlapping patterns and reducing interference of stored representations. It is highly susceptible to aging-related structural and physiological changes and thought to contribute to age-related cognitive dysfunctions. In this study we examined possible age-related changes in pattern separation function and associated changes in DG cellular engrams using a contextual fear conditioning task. Young adult (3-month-old) and healthy aged (24-month-old) C57Bl/6J mice were fear conditioned (three unconditional stimuli US foot shock: 0.4mA for 1s, aftershock interval: 20s) and examined for their fear response 1-day after the training in the original or in an altered context. Viral (AAV) delivery of a doxycycline-controlled tTA/TRE robust activity marking (RAM) system was used to label during the training and immunohistochemical labelling for cFos 90 min after memory retrieval to identify reactivated engram cells. Our data indicate that overall RAM labelling, cFos expression, and engram reactivation rate were significantly reduced in aged compared to young adult mice. However, we did not detect any difference between contexts or any correlation between the reactivation rate and freezing for both age groups. These data demonstrate that normal behavioural performance during context memory retrieval in healthy aged animals is maintained in spite of a reduced recruitment of DG engram cells.