Background: Thiols and ischemia-modified albumin (IMA) are novel biomarkers for the evaluation of the oxidative stress (OS) that has been associated with the pathogenesis of various neoplastic and inflammatory diseases. The aim of this study was to find out the dynamic thiol–disulfide homeostasis and IMA levels in patients with cutaneous mastocytosis (CM) to demonstrate the presence of the OS. Methods: A total of 36 patients with CM and 27 age- and sex-matched healthy participants were included in this study. Serum thiols and IMA levels were measured and compared between the 2 groups. Results: Levels of native thiol, total thiol, disulfide, disulfide/native thiol, disulfide/total thiol, native thiol/total thiol, and IMA were similar in both patients with CM and the control group. No significant difference was found with regard to mediator-releasing symptoms, clinical types, and remission status between the OS markers (thiol/disulfide variables and IMA levels) of the patients ( P > 0.05). Conclusions: To our knowledge, this study is the first study in the literature that investigated thiol–disulfide homeostasis and IMA levels in pediatric patients with CM. Our study indicated that OS plays no role in the course of the pediatric CM.