The blue-green sharpshooter Cicadella viridis (Linnaeus) (Hemiptera: Cicadellidae) is a significant pest and disease vector of some economically important plants in some parts of its range in the Palearctic and Oriental regions. Its alimentary canal was examined using the light and electron microscopes. The alimentary canal was differentiated into the esophagus, filter chamber, external midgut section, and hindgut. The filter chamber contained a sheath and a filter organ; the former externally surrounding the latter. The filter organ was composed of the anterior and posterior ends of the midgut (internal midgut section), internal proximal ends of the Malpighian tubules, and internal proximal end of the ileum. Two types of cells constituting the internal anterior end of the midgut possessed morphologically different basal infoldings and apical microvilli. Cells of the internal posterior end of the midgut contained concentric structures tentatively identified as modified basal plasma membranes, whereas plasma membranes of the internal proximal ends of Malpighian tubules invaginated into narrow sinuate basal infoldings, though both organs had similar reduced cytoplasm. The external midgut section was divided into a conical segment and a midgut loop. The conical segment cells, which were packed with mitochondria, possessed regularly arranged dense microvilli and shallow infoldings. The midgut loop was subdivided into two regions: 1) an anterior segment, with cells containing abundant electron-lucent secretory granules, ribosome-like particles, and sparse rough endoplasmic reticulum; and 2) a posterior segment, having numerous mitochondria, some lysosome-like granules, well-developed basal infoldings, and apical microvilli. The hindgut emerged from the posterior of the filter chamber and was composed of a pear-shaped rectum and a long narrow ileum. Its cells possessed apical leaflets associated with mitochondria. Microorganisms existing between lamina of the extracellular matrix, in a clearing of ileum cytoplasm and muscle fibers, are probably pathogenic.