Background <p>Suicide is a significant public health challenge in Iran, where cultural and religious factors influence both suicidal behavior and assessment approaches. This study aimed to validate the Persian version of the Brief Suicide Cognitions Scale (B-SCS) among individuals with suicidal thoughts in Iran, addressing a critical gap in culturally appropriate suicide risk assessment instruments.</p> Method <p>A cross-sectional study was conducted with 162 individuals experiencing suicidal ideation recruited from a psychiatric emergency department in Tehran. Participants completed the Persian B-SCS along with measures of depression, anxiety, hopelessness, and suicidal ideation. Confirmatory factor analysis examined the scale’s factor structure, while reliability was assessed through multiple indices. Convergent validity was evaluated through correlations with related constructs and calculation of Average Variance Extracted (AVE). Measurement invariance across gender was also examined.</p> Results <p>Confirmatory factor analysis strongly supported a unidimensional structure with excellent fit indices (<i>χ</i>²(9) = 10.262, <i>p</i> = .330, RMSEA = 0.021, CFI = 0.999, TLI = 0.998) and substantial factor loadings (0.85 − 0.92). The scale demonstrated excellent internal consistency (<i>α</i> = 0.956, ω = 0.957, CR = 0.956) and strong convergent validity, with significant correlations with depression (<i>r</i> = .977), hopelessness (<i>r</i> = .976), anxiety (<i>r</i> = .864), and suicidal ideation (<i>r</i> = .924). The AVE value (0.785) substantially exceeded the recommended threshold. Measurement invariance testing confirmed that the B-SCS functions equivalently across gender groups.</p> Conclusions <p>The Persian B-SCS showed strong psychometric properties, including excellent internal consistency, a clear unidimensional structure, and substantial convergent validity, providing robust preliminary support for its potential use in assessing suicide-specific cognitions in Iranian clinical settings.</p>