Umbilical endometriosis is an important differential diagnosis of any umbilical lesion. A 35-yearold type 2 diabetic woman presented with intermittent umbilical discharge which failed to respond to various antibiotics. An ultrasound scan and MRI scan failed to show any obvious abnormality. The umbilicus was excised and histology confirmed endometriosis. Surgical excision provides a definitive diagnosis and curative treatment for isolated endometriosis.