This study investigated whether microvessel density (MVD) and mast cell infiltration are related to prognosis in non-small cell lung carcinoma (NSCLC), and examined the possible role of mast cells in NSCLC angiogenesis. MVD and mast cell infiltration were analysed retrospectively in tumour specimens from 50 patients with primary NSCLC. Immunohistochemistry with monoclonal antibody anti-CD34 was used to delineate the microvessels and routine Giemsa blue staining was used to assess the number of mast cells. Significant correlations were found between MVD and mast cell infiltration and between MVD and both lymph node metastasis and tumour, node, metastases (TNM) stage. No significant correlations were found with respect to survival for MVD or mast cell infiltration. Multivariate analysis showed that TNM stage and tumour size were independent predictors of survival, suggesting that the TNM staging system remains the most important tool for the estimation of prognosis in NSCLC patients.