Purpose: To examine the associations between P wave, QT interval, and corrected QT interval dispersion and clinical pathologies in multisystem inflammatory syndrome in children (MIS-C). Methods: This study included 60 children diagnosed with MIS-C according to the US Centers for Disease Control and Prevention criteria and 26 healthy children. Their maximum and minimum P wave durations and QT interval durations were measured by 12‑lead surface electrocardiography. Results: P wave and QT interval dispersion were significantly greater in the children with MIS-C than in the healthy children (p < 0.001). In addition, P wave and QT interval dispersion were significantly greater before than after treatment among the children with MIS-C (p < 0.001). Conclusions: Our study found significantly greater P wave dispersion and QT dispersion in the patient group than in the control group. This correlates with the frequency of arrhythmias seen in MIS-C. We suggest that patients hospitalized with MIS-C should be meticulously monitored for potential arrhythmias.