The delay between the onset of symptoms and the call for help is the longest single component of the time taken for patients with acute myocardial infarction to come under coronary care and receive thrombolytic therapy. In order to investigate factors influencing patient delay, visual analogue scores for pain, shortness of breath, and anxiety were obtained retrospectively from 250 patients with acute myocardial infarction, for the time of onset of symptoms, and for the time of the call for help. The predominant symptom was chest pain, followed by anxiety and breathlessness. Although all symptoms increased in severity after their onset, the initiation of a call was largely unexplained in terms of worsening symptoms. Patient delay had a skewed distribution with modal, median and mean values of up to 1 h, 1.5 h, and 11 h respectively. Patient delay was negatively correlated with the pain score at the time of calling, but most of the variance of patient delay could not be explained in terms of symptom scores. However, patient delay was independently and negatively related to maximum serum aspartate aminotransferase. During acute myocardial infarction, patients with higher cardiac enzyme levels experience more pain and delay less. This tendency for patients with more severe infarction and a greater risk of death to call for help sooner is an added reason for administering thrombolytic treatment at the first opportunity: those patients who call early have most to gain from prompt therapy.