Incidental renal tumours are becoming an important clinical problem that many physicians will need to deal with. A good knowledge of the nature of these tumours and how to manage them is therefore needed. The aim of this paper is to review the literature about incidental renal tumours in adults. Many incidentally discovered small renal tumours (<4 cm) are benign and of low stage, grade and progression potential. The preferred management in young fit patients is open or laparoscopic nephron-sparing surgery. Treatment alternatives include needle-ablative therapies and surveillance in elderly unfit patients. Tumour renal biopsy is encouraged prior to needle-ablative therapy and surveillance. Awareness about incidental renal masses and their management is essential for treating doctors.