Abstract Aim Treatment of iron deficiency anaemia in patients undergoing colon cancer resection improves outcome defined by length of stay, recurrence, and requirement for blood transfusions. Method Retrospective analysis of patients with anaemia and colonic cancer between January 2018 - August 2019. Anaemia categorised as – Iron Deficiency Anaemia and non- Iron Deficiency anaemia. IDA was defined as hypochromic microcytic anaemia. Patient demographics, tumour location, pre- and post-operative haemoglobin, length of stay, recurrence and requirement for blood transfusions were collected plus treatment for anaemia. Comparisons made between IDA and non-IDA groups in relation to treatment for anaemia with iron (oral/IV). Non-parametric statistical tests used (median, 2-way ANOVA, Kruskal-Wallis) with significance at P <0.05. Results 150 patients with colonic cancer identified: 77 in IDA group, 46 treated (42 oral, 4 iv iron). 11 in non- IDA group, 8 treated (oral iron). IDA oral and IV treatment versus non-IDA: Median age 74, 80 and 78 years (P = 0.814), Pre- and post op Hb IDA vs non-IDA: 107, 97; 109, 101 (P 0.007 significant), Requirement for blood transfusion (units) 0.77, 0.50;0.90 (P 0.596) Length of Stay (days) 6, 5; 7 (P 0.113), Tumour location: mean of right colon and transverse colon 24.33, 3.667 (P >0.1), and Recurrence P >0.1. Conclusions In our series, iron treatment does not influence recurrence, length of stay, requirement for blood transfusions. Tumour location is not significantly different between IDA and non-IDA group. Patients treated with oral iron therapy are seen to have a larger drop in haemoglobin post operatively than the other groups.