Fifty-eight contributors from 12 European and 2 American sarcoidosis centers have collaborated in a survey to define many questions concerning the use of 67Ga lung scan in sarcoidosis. The new quantitative scoring methods based on digital evaluation seem better in detecting lung activity. In 20.1% of untreated patients, the 67Ga lung scan appeared to be the only noninvasive method with which clinical activity could be detected. 67Ga scans may be useful in guiding lung biopsy and in choosing pulmonary segments for BAL. Of 382 patients studied during follow-up (154 patients with three to nine scans at intervals of 2 to 12 months), the 67Ga scan was far more sensitive than chest radiography, both in detecting improvement and in foreseeing relapses. Steroid therapy appears to suppress ACE levels more than 67Ga uptake, and 67Ga uptake more than the alveolitis detectable by BAL. Gallium-67 uptake rebounds to positivity occur in about 40% of patients after steroid discontinuation and in about 20% of patients after steroid reduction to daily doses of 10 mg or less of prednisone. The 67Ga dose of 1.5 mCi seems appropriate for clinical purposes and is recommended for the subjective scoring method in order to reduce the cost and the radiation burden.