BACKGROUND: Minimizing time from onset of symptoms to treatment (treatment delay) is crucial for patients with ST segment elevation acute myocardial infarction (STEMI), and one of the great challenges is to reduce the delay relating to the prehospital behaviour of the patient (patient delay). Studies indicate that women delay longer than men and insights into this area could lead to improved health education programmes aimed at reducing patient delay in women with STEMI. METHOD: Open interviews with 14 women with STEMI were held during their hospital stay from June to September 2009. The interviews were aimed at exploring determinants of treatment delay, and were carried out and analysed within a phenomenological framework. FINDINGS: Three themes emerged important for the delay in seeking medical assistance: (1) Knowledge and ideas of AMI symptoms and risks. (2) Ambivalence whether to call for medical assistance or to cope with the situation. (3) Actions and strategies taken after onset of symptoms. CONCLUSIONS: Three factors determined whether women showed appropriate behaviour for reduced patient delay after onset of symptoms: (1) identifying the symptoms as being of cardiac origin, (2) having a prepared action plan in case of an emergency situation, and (3) living with someone or contacting other persons.