Objective. To describe global patterns among health-care accreditation organizations (AOs) and to identify determinants of sustainability and opportunities for improvement. Design. Web-based questionnaire survey. Participants. Organizations offering accreditation services nationally or internationally to health-care provider institutions or networks at primary, secondary or tertiary level in 2010. Main Outcome Measure(s). External relationships, scope and activity public information. Results. Forty-four AOs submitted data, compared with 33 in a survey 10 years earlier. Of the 30 AOs that reported survey activity in 2000 and 2010, 16 are still active and stable or growing. New and old programmes are increasingly linked to public funding and regulation. Conclusions. While the number of health-care AOs continues to grow, many fail to thrive. Successful organizations tend to complement mechanisms of regulation, health-care funding or governmental commitment to quality and health-care improvement that offer a supportive environment. Principal challenges include unstable business (e.g. limited market, low uptake) and unstable politics. Many organizations make only limited information available to patients and the public about standards, procedures or results.