The COVID-19 pandemic has marked the period from 2020 until today. It has led to frequent deaths, especially among the elderly population. With the emergence and increasing number of affected children, numerous research papers have been published on the impact of this infection on the pediatric population. In an effort to determine the clinical characteristics of infected children, we analyzed the medical history of 146 children hospitalized at the Pediatrics Clinic, Clinical Hospital Center Rijeka, from March 1, 2020, to June 1, 2022. A high prevalence of children with mild forms of the disease was observed, with a slight male predominance. A smaller number of children were asymptomatic. The most common mode of transmission was within the family. Non-specific symptoms were most predominant. Fever was the leading symptom. Analyzing the data, it was concluded that the lower respiratory tract was rarely affected in children. Eleven children had a severe clinical presentation, with a male predominance. Inflammatory parameters were often altered in laboratory findings. Elevated liver parameters and decreased kidney values were frequently found. Antiviral therapy was not used. Antibiotics and symptomatic therapy were most commonly used. Oxygen therapy was not necessary for the majority of children. Twenty-one children developed complications associated with COVID-19 infection. Twenty developed MIS-C, while one child developed ARDS. Involvement of the cardiovascular system was particularly noticed in children with MIS-C. Glucocorticoids, intravenous immunoglobulins, and antithrombotic therapy were typically used in the treatment of children with this complication. The mortality rate was less than 1%.