We aimed to assess sex differences in clinical characteristics, circumstances of arrest, and procedural characteristics in ST-elevation myocardial infarction (STEMI) patients with ventricular fibrillation (VF) prior to angioplasty.Cases of VF with first STEMI (n = 329; 276 men and 53 women) were identified from the GEVAMI study, which is prospectively assembled case-control study among first STEMI patients in Denmark.Compared to men, women experienced symptoms for a longer time interval prior to angioplasty (140 vs. 166 min, p = 0.020), and were more likely to present with VF later during transport to the hospital rather than prior to emergency medical services arrival (36 vs. 52%, p = 0.040). Prior to VF, women had a significantly lower income (p = 0.002) and education level (p = 0.008), were less likely to consume alcohol (3 vs. 6 units, p = 0.040), more likely to smoke (71 vs. 52%, p = 0.007), and more likely to have depression (25 vs. 10%, p = 0.002) or a history of angina (59 vs. 42%, p = 0.030). Even though women had more angina within a year prior to VF, no difference was observed in self-reported contact with the healthcare system (p = 0.200). In multivariable logistic regression models, history of angina (OR = 2.70; p = 0.006), low educational level (OR = 2.80, p = 0.012) and low income (OR = 6.00, p = 0.005) remained significantly associated with female sex. There were no differences in procedural characteristics between men and women.We found several sex differences in clinical characteristics and circumstances of arrest. The importance of seeking acute medical attention when experiencing angina should be emphasized in women, especially in women with low socioeconomic status.