This study will evaluate a complex intervention based on a patient management tool (PMT), combined with educational outreach to primary care doctors, nurses and other health workers, in the Brazilian city of Florianopolis. The intervention is aimed at improving the quality of respiratory care and respiratory health outcomes, and comorbid conditions, in adults with asthma and chronic obstructive pulmonary disease (COPD). The effectiveness of the intervention will be assessed by randomly allocating 48 primary care clinics to receive the intervention or not, and comparing patient and clinic level endpoints that reflect the health and quality of care provided over the following year. About 1250 patients known to have been diagnosed with asthma and 700 with COPD in participating clinics and will be included in the study. The primary endpoints for patients with asthma and COPD, respectively, will be composite scores indicating appropriate prescribing and diagnostic testing. The third primary endpoint, among all adult clinic users, will be rates of new diagnoses of asthma and COPD in each clinic. Secondary endpoints will include the individual components of the composite scores, health measures (hospital admissions and deaths), and indicators of appropriate management of comorbid conditions such as cardiovascular risk factors. Eligible patients will be identified and outcomes measured using electronic medical records.