Paleodietary analysis through the interpretation of stable isotopic analyses can be used to determine the approximate diet consumed at archaeological sites. The following question was investigated through the course of this research: What are the differences between the Middle Horizon capital of Tiwanaku and the associated colony of Chen Chen; and what do these differences, including those associated with paleodiet, suggest about interactions between the two sites? The main hypothesis suggested a similar dietary analysis between the two sites with two possible explanations. First, it is possible that similarities between the sites were due to the exchange and consumption of goods at both locations, perhaps through trade. Secondly, it is possible that the similarities were due to the acquisition of similar goods through local sourcing or limited trade. To assess this, an analysis was conducted based on δ13Cdiet (VPDB) values in the comparison of the city center Tiwanaku and the agricultural site of Chen Chen. Archaeological bone samples were processed from a diverse group of individuals at Chen Chen and combined with published values by Tomczak (2001), then compared against δ13C from Tiwanaku, published by Berryman (2010). After conversion to δ13Cdiet (VPDB) as described by Kellner and Schoeninger (2007), it was determined that there was no statistically significant difference between the δ13Cdiet (VPDB) values from either site, suggesting a similar ratio of goods consumed. These values were then compared to baseline values from the region to determine an approximate ratio of C3 to C4 flora or dependent fauna consumed. These data most likely support the second explanation of the main hypothesis, that both sites had access to similar goods through local sourcing or limited trade as an explanation for their similarity. However, because a similar ratio of foods consumed was determined in this analysis, it is still possible that trade occurred in both directions between Tiwanaku and Chen Chen. Additional isotopic analyses would be required to support the first claim, which can be addressed in future research projects.