An innovative mixed-method approach combining lexicometric (quantitative) and acceptability (qualitative) analysis is applied to measure consistency and adequacy levels of terminological decisions in international legal texts, and their adherence to recommendations found in the corresponding institutional terminological resources at three representative organizations: the European Union, the United Nations and the World Trade Organization. In line with a holistic approach to quality, the triangulation of findings points to a series of correlations between product quality indicators, translation process conditions and thematic competence specialization.