The present study investigated the effects of temporal grouping and intonation on immediate serial recall of digit lists in two conditions; a no-suppression and an articulatory suppression condition. In the no-suppression condition, in which only a memory task was required, a list of nine digits was recalled better when it was presented with intonation rather than without it. Furthermore, temporal grouping of items contributed to the recall performance of a digit-list more than the intonation did. These results indicated that prosody with which stimulus was presented could facilitate the immediate serial recall. In the articulatory suppression condition, in which the subjects were required to engage in both a memory task and irrelevant articulation, the effect of intonation disappeared. On the other hand, the grouping effect withstood articulatory suppression. The sources of memory improvement by prosodic information were discussed in terms of a working memory model.