Memory for associations is more vulnerable to aging than other aspects of episodic memory, but the factors that influence the magnitude of this age-related associative deficit remain to be determined. The present study examined how the visual complexity of items to-be-encoded as components of an association affects episodic memory for the association in young and older adults. In experiment 1, young adults encoded object pairs that were presented either as black line drawings (low visual complexity) or as color photographs (high visual complexity). Item, but not associative memory was improved in the high complexity condition. Event-related potentials recorded during item recognition suggested that item complexity reduced bottom-up item recollection, but enhanced top-down reconstruction of the study episode. Experiment 2 revealed that in older adults, both item and associative memory were enhanced in the high complexity condition, suggesting that older adults’ associative memory can benefit from detailed, complex item memory traces, presumably allowing for the (re-)construction of rich inter-item associative details. These results may provide the basis for instruction and training methods for older adults, directed at the manner in which item information is encoded, to optimize their associative memory.