Adrenocortical tumours are quite prevalent. Most of these tumours are benign, hormonally inactive adrenocortical adenomas. Rare hormone-secreting adrenocortical adenomas are associated with severe clinical consequences, whereas the prognosis of the rare adrenocortical cancer is rather poor in its advanced stages. The pathogenesis of these tumours is only partly elucidated. MicroRNAs are small, non-coding RNA molecules that are pivotal in the regulation of several basic cell biological processes via the posttranscriptional regulation of gene expression. Their altered expression has been described in many tumours. Several tissue microRNAs, such as miR-483-5p, miR-503, miR-210, miR-335 and miR-195 were found to be differentially expressed among benign and malignant adrenocortical tumours, and these could also have pathogenic relevance. Due to their tissue specific and stable expression, microRNAs can be exploited in diagnostics as well. As the histological diagnosis of adrenocortical malignancy is difficult, microRNAs might be of help in the establishment of malignancy. Novel data show that microRNAs are secreted in various body fluids, projecting their applicability as biomarkers as part of liquid biopsy. In this review, we attempt to present a synopsis on the pathogenic relevance of microRNAs in adrenocortical tumours and their potential diagnostic applicability. Orv Hetil. 2018; 159(7): 245-251.