Purpose: Anastomotic leak is a serious complication of colorectal surgery, with perfusion and height of anastomoses known to be risk factors. Indocyanine green (ICG) is commonly used in fluorescence angiography (FA) for perfusion assessment though techniques vary. This is a network meta-analysis comparing use of ICG-FA and height of anastomosis for left sided colorectal anastomoses and rates of anastomotic leak. Methodology: A systematic review was performed including all adult clinical studies using ICG-FA in colorectal anastomoses. A network meta-analysis was performed to compare high and low anterior resections and the use of ICG for the outcome of anastomotic leak. Results: Of some 49 clinical studies retrieved during review, 19 were included in meta-analysis in comparison of high and low anterior resection with and without ICG and anastomotic leak rates. Odds of leak were greater in low compared to high anastomoses, ICG is protective in both but odds of 0.42 (CI 0.29-0.58) show it is most protective in low anterior resection. Conclusion: There is benefit of ICG for both high and low colorectal anastomoses, but more so for low joins. Standardisation of technique with routine usage of ICG for low colorectal anastomoses should be considered.