The antennal sensilla of Anastrepha serpentina (Wiedemann) (Diptera: Tephritidae) adults were studied by means of scanning electron microscopy. Both sexes have the same form and number of antennal segments. The scape and the pedicel are covered entirely by microtrichia. In the distal part of both segments, a series of longitudinally striated hairs was observed, originating in a flexible socket and ending in a pointed tip. Six types of sensilla were observed in the funiculus: 1) thick-walled multiporous pitted sensilla subtype I and subtype II, 2) thin-walled multiporous pitted sensilla long subtype I and medium length subtype II, 3) basiconic sensilla, 4) multiporous grooved sensilla, 5) clavate sensilla, and 6) an olfactory pit with two small conical and striated sensilla inside. Furthermore, there is a large quantity of microtrichia surrounding the entire funiculus. In the proximal dorso-lateral region of the funiculus, there are trichoid aristae composed of two short segments and one large segment, which have fixed base bristles or tactile hairs without membranes. © 2009 Entomological Society of America.