The ultrastructure of the egg chorionic sculpturing of eight neotropical sand fly species (Lutzomyia townsendi (Ortiz, 1959), L. youngi Feliciangeli & Murillo, 1987, L. spinicrassa Osorno, Morales, Osorno, & Hoyos, 1969, L. evansi Nuñez Tovar 1924, L. lichyi, Floch & Abonnenc, 1950, L. trinidadensis Newstead, 1922, L. venezuelensis Floch & Abonnenc, 1948, and L. olmeca bicolor, Fairchild & Theodor, 1971) was studied using scanning electron microscopy (SEM). A new pattern, ellipses bound by fine longitudinal ridges, was observed in L. venezuelensis. Moreover, the chorionic ultrastructure was useful for separating three isomorphic species (L. townsendi, L. youngi, and L. spinicrassa), of which L. youngi and L. spinicrassa are sympatric in some endemic foci of Táchira State, Venezuela.