Aim. The aim of this study was to evaluate the incidence of diabetic ketoacidosis in children and adolescents with newly diagnosed type 1 diabetes in 2006-2007 and 2013-2014. Method. The study group consisted of 426 children aged 0–18 years with type 1 diabetes onset admitted to our hospital in 2006-2007 (group A) and 2013-2014 (group B). The study comprised the analysis of medical and laboratory records from patients' medical charts and the electronic database. Results. There was no difference between groups A and B in the percentage of children admitted with diabetic ketoacidosis (25% versus 28%, resp., P = 0.499). Among children with diabetic ketoacidosis, severe metabolic decompensation (pH < 7.1) appeared in similar frequency in groups A and B (28% versus 30%, resp., P = 0.110). In group B, children with diabetic ketoacidosis were statistically younger compared to patients without ketoacidosis (P = 0.015) and had higher HbA1c levels (P = 0.006). In both groups, a 2-fold increase in diabetic ketoacidosis was noted in children under the age of 3, compared to overall frequency. Conclusion. No decrease in diabetic ketoacidosis has been noted in the recent years. Although the prevalence and severity of diabetic ketoacidosis remain stable, they are unacceptably high. The youngest children are especially prone to ketoacidosis.