This study compared NRT-performance in monolingual Dutch and bilingual Turkish–Dutch third-graders using a Dutch Nonword Repetition Task (NRT). Several novel response analyses at the phoneme level were applied to further understand the earlier reported overall accuracy differences in NRT-performance between bilinguals and monolinguals. Analyses in which the retention of phonemes and the retention of their serial order were disentangled revealed that monolinguals outperform bilinguals with respect to the retention of the phonemes themselves. However, both groups did not differ in their retention of the serial order of correctly recalled phonemes. Furthermore, this study confirms that expressive vocabulary skills do affect overall NRT-performance. The results are discussed in light of current short-term memory (STM) models and the role of long-term phonological knowledge in NRT tasks.