This study examined the literature concerning the burdens of parents of preschool-aged children diagnosed with type 1 diabetes mellitus. We employed an integrative review methodology based on Whittemore and Knafl's framework. The literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines across four electronic databases: PubMed, Web of Science, the Cumulative Index to Nursing Allied Health Literature (CINAHL), and PsycINFO. Ultimately, 18 articles were included in the review. The review yielded four themes: (1) parental burdens, (2) factors related to the burdens, (3) coping strategies, and (4) implications for clinical practice. Parents experienced psychological, physical, and social burdens due to the diabetes care of their children. Several factors influenced burdens, including child-related characteristics such as age, severity of diabetes, and hospitalization experience, as well as parental factors like family income, race, and residential area. Parents initially felt burdened when their child was diagnosed with type 1 diabetes, but over time, they often adapted to the situation through support and sharing of responsibilities. Parents desired education and interventions reflecting the unique characteristics of preschoolers. This integrative literature review revealed that parents experience numerous burdens when their child is diagnosed with diabetes. Future research should focus on developing interventions to address parents' psychological difficulties, including tracking parental psychological changes over time. Tailored nursing interventions should also be provided to parents of preschool-aged children, as opposed to the more generic nursing interventions traditionally applied across all age groups of children in clinical settings.