Health professions educators are increasingly encouraged to implement "desirable difficulties" in their instruction, such as interleaved practice. In practical context, however, there is limited empirical evidence regarding the (meta)cognitive benefits of desirable difficulties, and interleaved practice in particular, posing a challenge to theoretical propositions. In this quasi-experimental field study, we examined the effectiveness of interleaved practice in auscultation training for second-year nursing students, with a focus on their learning outcomes and relative monitoring accuracy. Over 3 weeks, we measured participants' immediate and delayed-test scores, monitoring accuracy, and metacognitive knowledge of blocked and interleaved practice. Results revealed that interleaved practice yielded better auscultation performance than blocked practice. Regarding metacognitive accuracy, however, we found no statistically significant benefit of interleaving. Many students were unaware of the learning benefits of interleaved practice and found it more effortful than blocking. Our findings indicate that interleaved practice is a viable instructional method that can be utilized in authentic environments.