Colorectal (CRC) and gastroesophageal (GEC) cancers unusually spread to the bone. However, bone metastases (BM) are responsible for skeletal-related events (SREs) associated with an altered quality of life. Aiming to describe the characteristics and prognostic influence of BM from gastro-intestinal cancers, we performed a retrospective analysis of prospectively collected data in patients treated in our institution (1996-2006). 189 patients (5.5 %) developed BM: 79 with GEC and 110 with CRC. 57 patients had bone-exclusive metastases. In univariate analyses, the median time to BM occurrence was correlated with the primary tumour (PT) localisation, surgery, histology and TNM staging. However, in multivariate analyses, the occurrence delay was significantly shorter only for patients with GEC (HR 2.1), N1-2 status (HR 1.9), M1 status (HR 2.4), and epidermoid carcinoma (HR 6.0). Pain was the most frequent clinical sign leading to BM diagnosis (77.2 %). SRE occurred in 55 % of patients. Median overall survivals (OSs) of patients with CRC and GEC were 9.4 months [95 % confidence interval (95 % CI) 6.4-11.1] and 3.4 months (95 % CI 2.5-9.0), respectively. In univariate analyses, OS was correlated with PT surgery and NM staging, and the number of BM. In multivariate analyses, only the PT surgery and the number of BM remained correlated with OS. Our results suggest that there may be a subset of patients associated with a quicker development of BM. Given their higher risk of SRE, they could benefit from an early screening, calling for further prospective studies encompassing patients with and without BM.