Associated with treatments, breast cancer survivors (BCS) present fatigue and decreased cardiorespiratory capacity. The 6-minute walking distance test (6MWD) is used to assess the functional exercise capacity of BCS. Currently, there are different reference equations available; however, none of the existing models were built considering cancer survivor populations living above 2000 meters of altitude. We evaluated available reference equations for the 6MWD in sixty- four BCS females living at 2630 meters. Body composition and the 6MWD were measured by bioimpedance and the ATS 2002 protocol, respectively. Using stepwise multiple regression analysis, we constructed a reference equation. The following anthropometric traits were included as independent variables: height, weight, age, body mass index, percentage of maximum heart rate (HRF), final heart rate (FHR), percentage visceral fat (PVF), percentage muscle mass (PMM), body fat percentage (BTF) and oxygen saturation (FOS). We compared our new models and previously available reference equations. Multiple correlation analysis showed a significant association between 6MWD and height, as well as with four new anthropometric traits explored in this study (FOS, PVF, PMM and FHR). FHR, PVF, and PMM are the anthropometric traits that make up the “best” model, explaining 40.21% of the observed variability in 6MWD results. We concluded that the reference equations currently available are not the suitable to explain the observed variability in BCS living in highlands.