Background: Acute mastoiditis is a suppurative infection of mastoid air cells and is the most common intratemporal complication of otitis media. Aim: This study aimed to evaluate the demographic and clinical characteristics and treatment outcomes of children with acute mastoiditis (AM). Patients and Methods: We retrospectively reviewed the medical records of hospitalized pediatric patients aged between 1 month and 18 years with a diagnosis of AM between May 2015 and December 2021. Results: A total of 28 hospitalized children with AM were enrolled in this study, of whom 22 (78.6%) were males and 6 (21.4%) were females with a mean ± standard deviation age of 93.5 ± 53.2 months (range = 6 months-16.1 years). The most common clinical symptoms were postauricular erythema (n = 17, 60.7%), tenderness (n = 16, 57.1%), swelling (n = 14, 50%), fever (n = 14, 50%), and auricular protrusion (n = 7, 25%). Mastoiditis complications occurred in 10 (35.7%) children. The most common extracranial complication was subperiosteal abscess (n = 8, 28.6%). The erythrocyte sedimentation rate (ESR) and the rate of antibiotic use before hospitalization were higher in patients with complicated mastoiditis (P = 0.006 and P = 0.039, respectively). Surgery was performed in 12 (42.9%) patients. Statistically, more surgical interventions were performed in patients who developed complications (P = 0.003). Conclusion: AM continues as an important disease of childhood. Successful results are obtained with systemic antibiotic therapy and additional surgical intervention as necessary. A careful evaluation of patients with a high ESR and those who received antibiotic therapy before hospitalization is appropriate due to the correlation between these factors and the risk of complication development.