Because both articulatory rehearsal and attentional refreshing aid in the maintenance of verbal information in the short term, the present study evaluated the adaptive use of these mechanisms, using a complex span paradigm. In Experiment 1, the phonological similarity of memory list words and the attentional demand of concurrent processing were manipulated. As was predicted, a phonological similarity effect (PSE) appeared only when the concurrent task was attention demanding, thus impairing the use of refreshing and encouraging rehearsal. To verify that PSE indicates the use of rehearsal, participants were instructed to use one of the two mechanisms in Experiments 2 and 3. In accordance wih Experiment 1, the PSE was observed only under rehearsal. Thus, adults could adaptively choose between the two mechanisms. When remembering phonologically confusable materials, they prefer refreshing in order to reduce the impact of phonological characteristics. When available attention is reduced, they favor a less attention-demanding mechanism, rehearsal.