Our purpose was to understand premenstrual symptomatology and treatment-seeking behaviors by examining three subjective measurement approaches for premenstrual syndrome (PMS), their relationship to social functioning interference, and the role of symptom severity in a broader model of help seeking for PMS. Cross-sectional data were obtained from 1022 mail survey respondents who were derived from a nationally representative random sample of women, aged 18-49, experiencing regular menstrual cycles. Statistical analyses included Pearson correlations, chi-square tests, t tests, and logistic regression. The three symptom severity measures (a global self-appraisal, summative symptom counting, and categorical-configural) were strongly intercorrelated, ranging from. 60 to.78 (p < 0.001), and were correlated with interference in social and occupational functioning domains, ranging from.44 to.77 (all p < 0.001). A global self-report measure identified 4.9% of women with severe symptoms, whereas a DSM-IV-adapted approach identified 11.3% with premenstrual dysphoric disorder (PMDD) symptoms (of whom 92% also reported social interference). PMS treatment seeking was predicted by older age, PMS symptoms experienced in most cycles, greater self-reported symptom severity, greater overall use of healthcare services, and less negative attitudes toward PMS (all p < 0.05). These findings support the feasibility of clinician's use of brief screening approaches for PMDD, especially using short summative symptom rating scales. Women underidentify the severity of their PMS difficulties despite the reported difficulties associated with consistent social and occupational interference in most life domains. They are also reluctant to seek help for treatable PMS symptoms because of attitudinal barriers regardless of the severity of their PMS symptoms.