The implications of agro-biodiversity for nutrition were studied in traditional subsistence oriented mixed farming systems in an upland region of the Philippines. An interdisciplinary approach was adopted: firstly, the general dietary patterns were analyzed using data obtained mainly from semistructured guideline interviews. Secondly, a collection of 51 traditional landraces of upland rice, the most important staple food in these regions, was compiled and the nutritional value was determined. The diversity of the agricultural production was found to be important in ensuring food security and reducing the risk of temporary food shortages in the study area. The regular consumption of multiple species of vegetables and fruits provides a good source of micronutrients. The rice varieties cultivated in the area exhibited abundant morphological diversity and generally a high nutritional value. Crude protein content ranged between 7.0 and 13.7%, with an average of 9.5%. Crude lipid ranged from 0.8 to 3.2% with an average content of 2.3% and an average proportion of 79.6% of unsaturated fatty acids. The highest b-carotene contents were found in the colored varieties and reached up to 0.13 mg/g.