Background <p>Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental condition in children and adolescents that poses substantial challenges to health, functioning, and well-being. This study aimed to estimate the minimal clinically important difference (MCID) for the Chinese version of the Vanderbilt ADHD Parent Rating Scale (VAFPRS) and its key score domains using anchor-based and distribution-based methods.</p> Methods <p>In this multicenter prospective observational study, 99 children aged 4–17 years who were diagnosed with ADHD were recruited from four tertiary hospitals in China. Caregivers completed the VAFPRS at baseline and follow-up and the Clinical Global Impression–Improvement (CGI-I) scale at follow-up. MCID values were estimated using the anchor-based median change method, the receiver operating characteristic (ROC) curve method, and the distribution-based 0.5 standard deviation (SD) method.</p> Results <p>A total of 81 patients completed the follow-up assessment. CGI-I scores were significantly correlated with changes in the total VAFPRS score, core symptoms, inattention, and hyperactivity/impulsivity (<i>r</i> = 0.38–0.43, all <i>p</i> &lt; 0.01). The corresponding anchor-based median MCID estimates were − 8, −5, − 2, and − 3, respectively. ROC curve analysis yielded lower thresholds for these domains (− 3.5, − 2.5, − 1.5, and − 2.5), with acceptable discrimination (AUC ≥ 0.70) for identifying improvement.</p> Conclusion <p>This study estimated MCID values for the Chinese VAFPRS in children and adolescents with ADHD. Anchor-based median estimates derived from the minimally improved CGI-I group were − 8 for the total score, − 5 for core symptoms, − 2 for inattention, and − 3 for hyperactivity/impulsivity. ROC-derived thresholds were lower and may provide complementary classification cutoffs for identifying improvement status.</p> Clinical trial number <p>Not applicable.</p>