Vascular endothelial growth inhibitor (VEGI) is a novel anti-angiogenic cytokine that belongs to the tumour necrosis factor (TNF) superfamily. Very little is known about the significance of VEGI in cancer. Our study analysed VEGI expression in relation to breast cancer patient clinical parameters. The VEGI expression profile was assessed qualitatively (RT-PCR), quantitatively (real-time Quantitative-PCR), and immuno-histochemically (IHC), in a panel of 24 human normal and cancer cell lines and in a cohort of 151 mammary tissue samples (n = 33 normal breast tissue; n = 118 breast cancer tissue) with a 6-year median follow-up. Patients who had died of breast cancer or had local recurrence of the disease expressed significantly lower levels of VEGI in comparison to the elevated levels in the disease free patients. High levels of VEGI were associated with an increased chance of patient survival. Importantly, patients with breast tumours expressing reduced levels of VEGI had a poorer prognosis than those patients expressing high levels of VEGI. However, no significant correlations were observed between VEGI expression and tumour grade, TNM classification, or nodal involvement. In conclusion, VEGI is aberrantly expressed in human breast cancer tissues. VEGI displays prognostic relevance as breast cancer patients with an overall poor prognosis express significantly lower levels of VEGI compared to those with a favourable prognosis.