Objective: The objective of this study was to assess total energy expenditure (TEE), resting metabolic rate (RMR) and physical activity level (PAL), and to estimate energy requirements (ERs) in free-living elderly subjects from Cuba, Chile and Mexico. Design: Cross-sectional study designed to estimate ERs. Setting: Rural regions of Cuba, Chile and Mexico. Subjects: Forty subje cts >60 years old were selected to participate in this study. Interventions: A dose of doubly labeled water (DLW) was administered and urine samples were collected in the following 12-14 days. From the isotopic analysis, TEE was derived. RMR was measured by indirect calorimetry. Results: TEE in Chilean (8.8±1.6MJ/day) and Cuban (8.3±1.3MJ/day) elderly was not different, and was higher for the Mexican group (9.5±1.5MJ/day) (P<0.0001). RMR was not different between countries. PAL and activity energy expenditure (AEE) were only different between Chile and Mexico (P<0.002). For the three regions, overall PALs were 1.70±0.16 for male and 1.62±0.13 for female subjects (P<0.02), and AEE was 3.05±0.66 and 2.27±0.66MJ/day for male and female subjects, respectively (P<0.001). Predictive equations (MJ/day) were RMR=1.6447+0.05714 × weight (kg)+0.449 sex (male=1; female=0) (R2=0.75; SEE=0.479) and TEE=3.414+0.0795 × weight (kg)+1.227 × sex (male=1; female=0) (R2=0.75; SEE=0.668). Conclusions: There were differences in TEE and PAL owing to sex and region. The average PAL in men was higher than the PAL reported either with factorial approach or with the DLW method in elderly. Predictive ER equations based on RMR and TEE gave very similar results to calculations from the 2004 FAO/WHO/UNU report.