Although there is a worldwide interest in the assessment of health-related quality-of-life (HRQoL) in haemophilia patients, no non-disease specific instruments (for adults) are readily available. In this paper, a haemophilia-specific quality-of-life assessment measure for adults (the Hemofilia-QoL questionnaire) has been developed and tested for psychometric properties in 121 adults with haemophilia living in Spain. The Hemofilia-QoL questionnaire is a self-report modular instrument that assesses nine relevant HRQoL domains for patients with haemophilia (e.g. physical health, daily activities, joint damage, pain, treatment satisfaction, treatment difficulties, emotional functioning, mental health, relationships and social activity). Psychometric examination involved the assessment of data quality, scaling assumptions, reliability (internal consistency and test-retest) and validity (concurrent; external clinical criterion and sensitivity). The Hemofilia-QoL 36-item version questionnaire had acceptable internal consistency and retest reliability values. The questionnaire shows excellent concurrent validity (with the SF-36 Health Survey) and external clinical criterion validity (haemophilia clinical status) and sensitivity (health status changes) as well. The Hemofilia-QoL is now available for adult assessment and is ready for use in clinical research in Spain.