Purpose: Sarcopenia is a loss of muscle mass and function with age, and correlates with peri-operative morbidity and long-term survival. The most effective sarcopenia measure in estimating operative risk has not been established, and a breadth have been reported in the literature. We conducted a meta-analysis to identify which radiological sarcopenia measure best correlated with general surgical operative risk. Methodology: A systematic review and meta-analysis was conducted. Fifty papers relating to sarcopenia and general surgical outcomes were identified. Data from these was pooled and analysed to determine which sarcopenia measure was the most effective predictor of peri-operative morbidity. Results: 1.Sarcopenia predicted major complications (OR 1.42; 1.07-1.89) and mortality (OR 3.62; 2.69-4.88) 2.The effect size was larger following emergency (major complications OR 1.78; 1.35-2.33; mortality OR 4.97; 3.25-7.59), than elective general surgery (major complications OR 1.42; 1.04-1.94; mortality OR 2.64; 1.82-3.84) 3.Psoas muscle density was the most effective predictor of major complications (OR 3.71; 1.75–7.89) and mortality (OR 9.47; 4.35–20.64) 4.Psoas muscle area also predicted major complications (OR 1.89; 1.08–3.42) and mortality (OR 4.18; 2.63–6.65), however the effect sizes were smaller than for psoas muscle density 5.Post-operative mortality also correlated with total skeletal muscle density (OR 2.84; 1.08–7.46) and total skeletal muscle area (OR 2.55; 1.57–4.12), however effect sizes were smaller, and these measures did not correlate significantly with major complications Conclusion: Sarcopenia correlated with general surgical outcomes, with a larger effect size for emergency than elective surgery. Outcomes were more effectively predicted by psoas muscle than total skeletal muscle measures; and by density rather than area measures. Psoas muscle density was the most effective radiological sarcopenia measure identified in this study.