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Introduction: Venous invasion is an important high risk feature in colorectal cancer. However, prevalence of venous invasion in published studies ranges from 10-90%. To resolve disparity amongst reporting pathologists in our institution, methods to improve detection of vascular invasion were sought. Elastica stains highlight elastin fibres present in the adventitia of blood vessels providing a more objective method of detection of venous invasion. As a result elastica stains have been used routinely on colorectal specimens in our institution since 2002. The aim of the present study was to examine the impact of elastica staining on the value of venous invasion as a predictor of cancer specific survival, following curative resection of colorectal cancer. Methods: 419 patients underwent curative elective colorectal cancer resection between 1997-2006. Patients were grouped prior to (1997-2001(cohort 1, n=194)) and following introduction of elastica staining (2003-2006 (cohort 2, n=225)). In a third cohort 53 patients between 1997-2000, both H&E alone and elastica H&E techniques were applied allowing a direct comparison within a single cohort.Results: Clinico-pathological characteristics and 3-year survival rates were similar in both groups (cohort 1 vs cohort 2). Rate of detected venous invasion increased from 18% to 58% following introduction of elastica staining (p<0.001). The 3-year cancer survival rate associated with absence of venous invasion was 84% in cohort 1, compared with 96% in cohort 2 (P<0.01). Elastica staining improved the prognostic value of venous invasion; the area under the receiver operator curve rising from 0.59 (P=0.040;1997-2001) to 0.68 (P<0.001;2003-2006) using cancer mortality as an endpoint. Within cohort 2, the absence of venous invasion was associated with a 3 year cancer survival of 96% in both node negative and node positive disease. A direct comparison between H&E alone and elastica H&E was made in 53 patients (cohort 3). The area under the receiver operator curve rose from 0.58, P=0.293 (H&E alone) to 0.74, P=0.003 (elastica H&E).Discussion: Increased detection of venous invasion with elastica staining, compared with H&E alone, provides superior prediction of cancer survival in colorectal cancer. This relationship was seen in the comparison of two consecutive cohorts and in a direct comparison in a single cohort. When stained with elastica, the absence of venous invasion is associated with an excellent 3 year survival whatever the tumor’s lymph node status. Based on these results, elastica staining should be incorporated into the routine pathological assessment of venous invasion in colorectal cancer.