Most of the focus in choroidal and retinal angiogenesis centers on the regulation of endothelial function by soluble factors. Less well-understood, but nevertheless significant, is the regulation of endothelial cell function by its insoluble microenvironment, the extracellular matrix (ECM). Endothelial interaction with the ECM occurs primarily through cell surface receptors belonging to the integrin family that relay information from the ECM to the intracellular signaling machinery. The integrin family is composed of 24 heterodimeric type I transmembrane cell surface receptors containing an alpha and a beta subunit. To date, there are known to be 18 alpha and eight beta subunits [1]. Alpha subunits are designated 1–11, iib, v, D, E, L, M, and X. Beta subunits have designations of 1–8. The heterodimeric receptor is designated through identification of the corresponding alpha and beta subunits, e.g., αiibβ3 designates the platelet integrin. The ECM specificity of individual integrin family members covers a broad spectrum of selectivity as exemplified by the restricted specificity of the α5β1 integrin for only fibronectin and the promiscuous binding of the αvβ3 to a diverse set of ECM [2]. Even with this disparity in matrix selectivity, integrin family members can be categorized based on the subset of matrices recognized and cell type expression patterns. The four categories consist of integrins that preferentially bind collagen, laminin, or ECM containing an arg-gly-asp (RGD) tripeptide motif and integrins which are primarily leukocyte-specific receptors [1, 2]. The ability of a number of integrins to recognize the same primary matrix implies that there is potential overlap among family members. While there clearly can be some degree of functional compensation, as seen in the ability of the αvβ3 integrin to supplement fibronectin matrix assembly in the absence of α5β1 integrin [3], this functional compensation is incomplete, implying that each family member is likely to have a crucial functional role within a given biological process. The functional activity of integrin family members can be typically viewed as having a permissive role in providing adhesive function; however, in some cases, this role may be regulatory rather than permissive in nature, as in the case of the αvβ3 integrin, which is believed to modulate neovascular response [4]. Furthermore, the functional activity may also depend on the presence of other integrin family members, which may suppress function via a mechanism of transmodulation known as transdominance [5, 6]. It is clear that in order to gain a better understanding of how cell adhesion, and especially integrins, regulate a biological process, it is essential to understand the repertoire of integrins involved and their expression relative to disease progression. During neovascularization, several integrin family members have been implicated in regulating endothelial cell function, including α1β1, α2β1, α5β1, αvβ3, and αvβ5 [7]. In ocular neovascular membranes (POHS, idiopathic, choroidal neovascular [CNV], PVR, and PDR), integrin expression has been studied in only a few instances [8–10], with focus on either a subset of receptors [8, 9] or the examination of a broad range of integrin subunits in a small number of membranes [10]. To obtain a more comprehensive understanding of integrin family member expression in neovascular progression, we examined the expression of α1β1, α2β1, α5β1, αvβ3, and αvβ5 integrins in surgically removed subretinal membranes with an emphasis on identifying integrins expressed primarily on endothelial cells. In the present study, surgically removed human CNV membranes, for which the patient histories and disease progression are known, were characterized for integrin expression relative to the endothelial markers CD31 and VWF. Consistent with known neovascular responses, endothelial staining correlated well with patient histories, with endothelial staining in active and mid stage disease, but little or no staining of endothelial cells in tissues from late stage and fibrotic membranes. Integrin staining was primarily seen in early and mid stage where αvβ3, α1β1, α2 β1, and α5β1 staining colocalized with endothelial cells. No correlation between αvβ5 staining and endothelial cells was observed.