Few cross-cultural studies have assessed psychopathy and none have included a sample from non-western countries. This study investigated the factor structure of the Psychopathy Checklist: Screening Version (PCL:SV) in an Iranian sample, and compared the results with a western sample. Three hundred fifty-one Iranian prisoners were compared with 405 participants of the standardization sample of the PCL:SV. Confirmatory factor analysis and item response theory method were used for data analysis. The Iranian data fitted well with the hierarchical three-factor model of psychopathy and neither two- nor four-factor models showed an adequate fit. Differential item functioning existed across samples, with discriminatory power of factor 1 (arrogant and deceitful interpersonal style) being lower in the Iranian sample that for factor 2 (deficient emotional experience) being greater in the Iranian sample than the standardization sample. Deficient emotional experience might be the most significant factor in diagnosing psychopathy, regardless of the studied culture. Other factors appear to be relatively culture-specific.