SUMMARYCarbon footprinting is an increasingly important method of communicating the climate change impacts of food production to stakeholders. Few studies utilize empirical data collected from farms to calculate the carbon footprints of lamb and beef. Data from two farms in Wales, UK, were employed to undertake such an analysis for two system boundaries.Within a system boundary that considers the embodied greenhouse gases (GHGs) in inputs and on-farm emissions, producing 1 kg of lamb releases 1·3–4·4 kg CO2 eq/kg live weight (case study farm 1) and 1·5–4·7 kg CO2 eq/kg live weight (case study farm 2). The production of beef releases 1·5–5·3 and 1·4–4·4 kg CO2 eq/kg live weight.Within a wider system boundary that also includes GHG emissions from animals and farm soils, lamb released 8·1–31·7 and 20·3–143·5 kg CO2 eq/kg live weight on the two case study farms, and beef released 9·7–38·1 and 18·8–132·6 kg CO2 eq/kg live weight. The difference in emissions for this system boundary relates to nitrous oxides emitted from the organic soils on case study farm 2.These values overlap with nearly all other studies of GHG emissions from lamb and beef production. No direct comparisons between studies are possible due to substantial differences in the methodological approaches adopted.