The purpose of this study was to determine the relationship between body mass index (BMI) and waist-to-hip ratio with the flexibility of the elderly. This experimental study involved 50 elderly consisting of 11 elderly men and 39 elderly women spread from the age of 46 years to 69 years. Waist to Hip Ratio was obtained from waist circumference (cm) divided by hip circumference (cm). Measurement of flexibility in the elderly was carried out using the chair sit and reach instrument. The results showed that the normality test with the one sample Kolmogorov Smirnov test showed that all variables had a significance value (p > 0.05), BMI = 0.200, waist to hip ratio = 0.200 and chair sit and reach = 0.200. The Pearson correlation test was used to test the correlation between research variables which showed a significance value (p > 0.05) on the relationship between BMI and flexibility (p = 0.098) and waist to hip ratio with flexibility (0.603), so that the variables studied did not have a relationship. This study showed that body mass index has a relationship with waist circumference, hip circumference, and waist-to-hip ratio. Although the results of the study showed that there was no significant relationship between body mass index and waist-to-hip ratio with elderly flexibility, maintaining BMI in normal conditions and waist to hip ratio in conditions that were not obese was able to maintain the health of the elderly to avoid degenerative diseases and metabolic syndrome.