The spread of agropastoralism in the South-Central Andes involved diverse local adaptations that are often difficult todetect due to poor preservation of organic remains. To address this challenge, we conducted a large-scale organic residuestudy of 172 Formative Period (200–800 CE) pots from three contemporaneous villages in the Tafí Valley, northwesternArgentina. Using gas chromatography–mass spectrometry (GC-MS), compound-specific isotope analysis (GC-C-IRMS),and bulk isotope analysis of charred food crusts (EA-IRMS), we reconstructed subsistence practices and local foodwaysacross distinct micro-environments. Biomolecular and carbon-stable isotopes on lipids and charred food crusts (δ¹³C)showed the exploitation of C3 plants and ruminant animals and a clear regional patterning of broad subsistence strate-gies. These findings provide the first direct chemical evidence of subsistence micro-diversity within the Southern Andes,demonstrating that neighboring communities pursued distinct combinations of farming and herding despite similar culturaltraditions. Methodologically, the study highlights both the potential and limitations of lipid residues for detecting plant usein South American contexts, and underscores the need for expanded regional reference datasets.