The helix-loop-helix transcription factor Id-1 (an inhibitor of differentiation and DNA binding) plays a role in development and progression of many tumours. Id-1 is known to exert its effects on the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor (VEGF). The aim of this study was to reveal whether there was a relationship between Id-1 and EGFR and VEGF in colorectal carcinoma.