Objective: To evaluate the expressions of nuclear factor nB (NF-nB p65), inducible nitric oxide synthase enzyme (iNOS), and vascular endothelial growth factor (VEGF) in relation to angiogenesis (microvessel density, MVD) and clinical outcomes in adenoid cystic carcinoma (ACC) of salivary glands. Methods: Immunohistochemical staining was used to quantify the protein expression levels of NF-nB p65, iNOS, and VEGF in 80 surgically resected ACCs and 20 normal salivary tissues. In all cases of ACCs, MVDwas evaluated by counting CD34-reactive endothelial cells or endothelial cell clusters. Results: The nuclear localization of NF-nB p65 was only detected in ACC cells. Both iNOS and VEGF staining activities in ACCs were more significant than those in normal gland tissues (P<0.01). MVD had significant correlations with NF-nB p65, iNOS, and VEGF expressions (P<0.01). In three histologic types of ACCs, the NF-nB, iNOS, VEGF expressions, andMVDwere significantly higher in solid type than in cribriform and tubular types (P<0.01).The NF-nB, iNOS, VEGF expressions, and MVD were significantly correlatedwith clinical stage, tumor size, vascular invasion, recurrence, and metastasis (P<0.05). Multivariate analysis showed NF-nB, iNOS and VEGF expression, MVD, solid histotype, and perineural invasion had an independent prognostic effect on overall survival. Conclusion: The expressions of NF-nB p65, iNOS, and VEGF were related with MVD. Clinical outcomes raised the possibility that the overexpression of these cytokines might contribute to tumor angiogenesis and have prognostic value in ACCs.