Two patients with chest infections caused by Actinomyces meyeri were seen during a 5-yr period. One patient was ill for 2 yr and had chronic infection manifested by bilateral cavitary and fibrotic changes on chest roentgenogram. A. meyeri was isolated from a chest wall lesion, transtracheal aspirate, and lung tissue. The other patient presented with a subcutaneous abscess of the left hip that yielded A. meyeri on culture. A localized lung infection and empyema were found. Both patients had other aerobes or anaerobes recovered from material haboring A. meyeri, a frequent finding in actinomycosis caused by Actinomyces israelii. To our knowledge, thoracic actinomycosis caused by A. meyeri has not been previously described.