Buying foods locally may reduce food-miles and the associated transportation green-house gas emissions. This study shows how existing extended input-output lifecycle analysis (EIO-LCA) literature on transportation greenhouse gas (GHG) emissions of local food sys-tems may lead to biased estimates. We develop a modified EIO-LCA model that corrects this problem. This paper illustrates the approach and demonstrates to what extent the results might be biased if these issues are not corrected. As the biases can be large, this finding and the modified method are meaningful and informative for local food policy makers and re-searchers who wish to assess the impact of local foods on GHGs.