Abstract Online pornography use has increased worldwide in recent decades, with problematic use being associated with negative mental health outcomes. However, no brief instrument is currently available to specifically assess Problematic Pornography Use (PPU) by operationalizing the behavioral manifestations of Compulsive Sexual Behavior Disorder (CSBD) as defined in the 11th International Statistical Classification of Diseases (ICD-11). This study aimed to develop the Compulsive Pornography Use Scale (CPUS-4). The sample consisted of 1,023 Czech adults that completed an online survey assessing pornography use behaviors, Pornography Addiction Screening Tool (PAST), Depression, Anxiety, Stress Scales-21 (DASS-21), and Three-Item Loneliness Scale (UCLA-3). Exploratory and confirmatory factor analyses indicated a single-factor structure of the CPUS-4, supporting its factorial validity. The scale demonstrated high internal consistency and significant associations with theoretically related constructs, supporting both convergent and concurrent validity. Overall, the CPUS-4 appears to be a valid and reliable brief instrument for assessing pornography-related behavioral manifestations within the ICD-11 framework for CSBD.