INTRODUCTION: Opening pressure in lumbar puncture (LP) is an important parameter in the diagnosis of various neurological diseases. In children pressures may vary according to age. This study aimed to analyze the variation of opening pressure in LP according to age in children. METHODS: All LPs performed between February 2017 and March 2023 were analyzed. Patients with modifying factors for opening pressure were excluded. Descriptive analysis was conducted, along with a comparison of means and medians, local regression, and quantile regression. To identify the most relevant cutoff points, graphical analyses were employed. RESULTS: The median opening pressure was 21.0 cm H CONCLUSION: Opening pressures in children vary with age, with no differences related to sex. Graphical analysis indicates that 96 months of age is an important cutoff point. Above this age, standard values could be used, up to 96 months of age, however, it is necessary to conduct studies for reference values. Opening pressure alone is not sufficient for the diagnosis of intracranial hypertension in children.