Background <p>Blind boxes are gambling-like products with increasing popularity worldwide. Accumulating evidence has shown that blind box over-purchasing is a rising problem, yet no validated tool exists for its addictive components. Besides, the link between problematic blind box buying and gambling disorder (GD) has never been tested. To fill these knowledge gaps, the current study tested the psychometric performance of the Problematic Blind Box Buying Scale (PBBS) and further examined the associations between problematic blind box buying and GD at both construct and symptom levels using bivariate correlation and network analysis, respectively.</p> Methods <p>The sample consists of 1324 Chinese adults (52.3% female, M_<i>age</i> = 33.13, SD_<i>age</i> = 6.73) who have experience with blind box buying.</p> Results <p>Results from exploratory and confirmatory factor analysis consistently suggested the unidimensionality of PBBS. This scale also showed good internal consistency, convergent validity, and concurrent validity. The positive correlations between problematic blind box buying and GD were found at both construct and symptom levels. <i>Chasing loss</i> was the central node, while the <i>conflict</i> symptom of GD and the <i>relapse</i> symptom of problematic blind box buying were the bridge symptoms in the network of problematic blind box buying and GD.</p> Conclusions <p>The current study is the first exploratory investigation of problematic blind box buying and its relationship with GD. It provides evidence for the validity and reliability of PBBS for measuring problematic blind box buying. Moreover, its findings also support the addictive potential of blind box buying and the associated risk with gambling disorder. These findings provide practical insights for the regulation and policy of blind box commerce and GD intervention.</p>