BACKGROUND Metastasis of bronchogenic carcinoma to axillary lymph nodes is rare. The pathways and possible significance of axillary lymph node metastasis from bronchogenic carcinoma were investigated. METHODS Seventeen patients with probable axillary lymph node metastases from bronchogenic carcinoma were identified by computed tomography. There were 15 nonsmall cell lung cancers and 2 small cell lung cancers. Axillary lymph node metastasis was proven by biopsy in six cases. Metastases were presumed because of an increase in the size of axillary lymph nodes compared with prior studies in six patients and enlarged axillary lymph nodes associated with biopsy-proven ipsilateral supraclavicular lymph node metastasis in five patients. RESULTS Four of 10 right-sided lung cancers had ipsilateral and six had contralateral axillary lymph node metastases. Six of seven left-sided cancers had ipsilateral and one had contralateral axillary lymph node metastases. Patients with ipsilateral lymph node disease had chest wall involvement and/or supraclavicular and mediastinal lymph node metastases. All seven patients with contralateral axillary lymph node metastases had supraclavicular and/or mediastinal lymph node metastases. CONCLUSIONS Bronchogenic carcinoma may involve ipsilateral axillary lymph nodes via either chest wall invasion or retrograde spread from supraclavicular lymph nodes. Contralateral axillary lymph node involvement requires involvement of contralateral mediastinal and supraclavicular lymph nodes with retrograde spread to the axillary lymph nodes.