A comparative cohort study was carried out of 164 patients (107 men, 57 women, median age 68 years) who underwent major colorectal surgery. Details obtained included demographic and operative information, the number of units of blood cross-matched, units used, the reasons for transfusion and patient suitability for electronic issue (EI). The cross-match to transfusion ratio (C:T ratio) was calculated for each procedure and for the whole group of colorectal procedures.