Incidentalomas can be defined in a variety of ways: 1) Imaging abnormality in a healthy, asymptomatic patient; 2) Imaging abnormality not related to a patient’s symptoms or the organs in question; 3) Findings discovered by chance which can potentially affect the health of a patient. This is a very interesting umbrella review. The authors included 240 primary studies from 20 systemic reviews. The worrying question is always if these incidentalomas are malignant. In this article, the prevalence of malignancy in incidentalomas is reported as follows: Brain, parotid and adrenal gland – less than 5%; Prostate and colon – 10-20%; Renal, thyroid and ovarian – 25%. Our primary aim is to do no harm. Therefore such findings should be fully discussed in multidisciplinary team meetings and with the patient before embarking on further interventions. Unexpected findings such as these can cause great anxiety to patients, families and create a financial burden on health services.