To assess the prevalence of anti-thyroid antibodies (AB) in pediatric patients with immune thrombocytopenia (ITP). This cross-sectional study included 50 ITP cases recruited at the Hematology Unit of the Pediatric Department at Menoufia University Hospital, along with 50 healthy controls matched by age and sex. Laboratory tests included complete blood count, measurement of antithyroid AB (anti-thyroid peroxidase (TPO) and anti-thyroglobulin (TG)), lactate dehydrogenase (LDH) and serum fibrinogen. The study was approved by the Institutional Review Board (IRB) of the Menoufia Faculty of Medicine (approval ID number: 4/2020PEDI12). Research was performed in accordance with the Declaration of Helsinki. Written informed consent was obtained from the patients’ parents and caregivers after explaining all aspects of the study, with the right to withdraw at any time. TPO and TG antibody levels were significantly higher in the cases than in the controls (p-value = 0.001). The chronic ITP cases showed significantly higher TPO and TG AB levels than the newly diagnosed ITP patients (p-value = 0.001). There was no significant difference between males and females in terms of anti-TPO levels (p-value > 0.05). A significant negative correlation was found between anti-TPO levels and LDH levels (r = –0.0326, p-value = 0.021) and a significant positive correlation – between anti-TPO levels and TG antibody levels (r = 0.360, p-value = 0.01). TG and anti-TPO AB levels were elevated in the children with ITP, particularly in cases of chronic ITP, with the cut-off point for chronicity being > 12.8 for anti-TPO and > 11.8 for TG antibodies.