Background <p>Anxiety disorder is a common psychiatric condition in pediatric populations that may become chronic and impair functioning if left untreated. Chromogranin A (CgA) is a polypeptide co-secreted with catecholamines in response to stress and anxiety. The association between CgA and anxiety disorder has been investigated in adult populations; however, data in children and adolescents remain limited. This research sets out to analyze, for the first time, plasma CgA concentrations in medication-naïve children and adolescents diagnosed with anxiety disorders and to contrast these findings with data obtained from a control group.</p> Methods <p>This cross-sectional study included 37 medication-naïve children and adolescents aged 9–18 years diagnosed with anxiety disorders and 34 controls with similar age and sex distributions. Plasma chromogranin A (CgA) concentrations were measured using an enzyme-linked immunosorbent assay (ELISA) and compared between the groups. The parents of all participants competed the SCARED Parent Form.</p> Results <p>Total and subscale SCARED scores were significantly higher in the anxiety disorder group compared with controls (all <i>p</i> &lt; 0.001). Plasma CgA levels exhibited no significant intergroup variation between AD and control groups (<i>p</i> &gt; 0,05). Correlation analyses revealed no significant associations between plasma CgA levels and SCARED total or subscale scores (all <i>p</i> &gt; 0.05). Among sociodemographic variables, only family structure differed significantly between the groups (<i>p</i> = 0.012).</p> Conclusions <p>In pediatric populations, no significant difference in plasma CgA levels was observed between anxiety disorder and control groups, in contrast to findings in adult studies. This discrepancy may be related to developmental factors such as autonomic nervous system maturation and hormonal changes. Further studies are needed to clarify the role of CgA in the pathophysiology of anxiety disorders in children and adolescents.</p>