We present the case of a patient with initially insignificant coronary atherosclerosis with rapid progression revealed by dobutamine stress echocardiography, despite the absence of a major risk factor. A 61-year-old woman, complaining of chest pain, palpitations and dyspnoea on exertion, was referred to our department for outpatient assessment. Coronary angiography performed two months earlier revealed an insignificant stenosis of the proximal left anterior descending coronary artery. Holter monitoring revealed malignant ventricular arrhythmias during angina episodes.The results of maximal treadmill exercise testing were negative, but those of the dobutamine stress echocardiography were positive. The angiographic re-evaluation revealed a rapid progression of stenosis of the proximal left anterior descending coronary artery. Percutaneous coronary angioplasty with stenting was successfully performed.The outcome of patients with insignificant angiographic stenosis and no major risk factor is not necessarily favourable. Therefore, these patients should receive intensive therapy for the management of risk factors and careful clinical monitoring, including dobutamine stress echocardiography.