Isavuconazole is the latest triazole broad-spectrum antifungal drug that has been approved for the treatment of invasive aspergillosis and mucormycosis in adults. When isavuconazole was initially marketed abroad, many international guidelines did not recommend or weakly recommended it for routine therapeutic drug monitoring. However, a number of recent studies and expert consensus have emphasized that specific populations can be monitored for the use of isavuconazole based on clinical needs. Based on domestic and international real-world studies, this article provided a review of the specific situations leading to therapeutic drug monitoring of isavuconazole, including liver insufficiency, abnormal body mass index, children, CYP3A5*1/*3 genotypes, multi-drug therapy, long-term medication, and receiving special treatment or medication regimens, in order to provide reference for the clinical rational application of isavuconazole.