BACKGROUND: There is a need to establish whether the structure of asthma care in general practice is associated with measures of process and with primary and secondary care clinical outcomes. Debate about how to resource general practice asthma care is hampered by a lack of observational data from throughout the United Kingdom (UK). AIM: To observe whether the present system of family health services authority (FHSA) accreditation of asthma clinics, based on measures of structure, is associated with measures of process or clinical outcome. METHOD: Two hundred and twenty-five UK practitioners enrolled in a project and recorded details of how they organized asthma care. Data from 6732 patients, concerning general practitioner and nurse consultations, asthma attacks, symptom control, emergency treatments and hospital attendances covering a 12-month period, were also provided. RESULTS: FHSA approval for a chronic disease management (CDM) asthma clinic was associated with favourable patterns of structure and process, but not of clinical outcome. Practice audit and the employment of a nurse with an asthma diploma were associated with favourable patterns of structure, process and clinical outcome. Practices (n = 143) that had recently audited asthma patient care (n = 4259) had fewer patients who had attended an accident and emergency department [121 (3%): 96 (4%), odds ratio 1.38, 95% confidence interval 1.04-1.83] or a hospital outpatients department [247 (6%): 180 (7%), 1.28, 1.04-1.56], or who had respiratory symptoms on assessment [2400 (56%): 1465 (59%), 1.34, 1.18-1.52] or days absent from work or school in the past 12 months [375 (9%): 296 (12%), 1.48, 1.25-1.74] than those that had not (82 practices, 2473 patients). CONCLUSION: Findings from a large UK sample of practices are subject to participant bias and show association rather than causal links. The present FHSA asthma CDM accreditation system, based on structure, is not associated with favourable clinical outcomes. This opens the debate as to whether accreditation should be linked to recent experience of audit, which does appear to be associated with favourable clinical outcomes.