Background and aims Pathological buying (PB) is a behavioral addiction that presents comorbidity with several psychiatric disorders. Despite the increase in the prevalence estimates of PB, relatively few PB instruments have been developed. Our aim was to assess the psychometric properties of the Spanish version of the pathological buying screener (PBS) and to explore the associations between PB, psychopathology, and personality traits. Methods A total of 511 participants, including gambling disorder (GD) and eating disorder (ED) patients diagnosed according to DSM-5 criteria, as well as healthy controls (HCs), took part in the study. Results Higher PB prevalence was obtained in ED patients than in the other two study groups (ED 12.5% vs. 1.3% HC and 2.7% GD). Confirmatory factor analysis (CFA) verified the 13-item structure of the PBS, and indexes of convergent and discriminant capacity were estimated. CFA confirmed the structure in two factors (excessive buying behavior and loss of control) with excellent internal consistency (α = .92 and .86, respectively). Good convergent capacity was obtained with external psychopathology and personality measures (positive correlations with novelty seeking and negative associations with self-directedness and harm avoidance were found). Good discriminative capacity to differentiate between the study groups was obtained. Discussion and conclusions This study provides support for the reliability and validity of the Spanish adaptation of the PBS. Female sex, higher impulsivity, and higher psychopathology were associated with PB.