Gastric filling induces activation of vagal afferent fibers, which participate in peripheral signaling to the CNS for control of food intake. It is not known, whether these afferent fibers linearly encode the increasing contractions of the antrum during antral distension (AD). The objective of this study was to investigate the effects of AD and electrically enhanced antral contractions on responses of vagal afferent fibers innervating the antrum. Extracellular single-fiber recording was made from the vagal afferent fibers from anesthetized male Long-Evans rats. The antral motility was measured with a solid-state probe positioned inside a small balloon placed into the antrum. A sub-threshold electrical stimulus, which did not cause smooth muscle contraction, was applied to the antrum during the ascending phase of distension-induced antral contractions. This signal enhanced the ongoing antral contractions. Fifty-six fibers identified to AD (1ml for 30s) were studied for their responses to different types of mechanical stimuli. Under normal non-distended condition a group of fibers exhibited rhythmic firing in phase with antral contractions. Another group of fibers had non-rhythmic spontaneous firing, which responded to enhanced antral contraction. Responses of 15 fibers were tested with non-excitatory electrical stimulation (NES) to the antrum during MSD. NES produced a mean increase in antral contraction amplitude (177.1 ± 35.3%) and vagal afferents firing frequency (21.6 ± 2.6%). Results indicate that both passive distension and enhanced antral contractions activate distension-sensitive vagal afferent fibers innervating the antrum. Responses of these fibers encode linearly to enhanced antral contraction induced by MSD or NES up to a distending volume of 0.6 ml. However, the responses reached a plateau at distending volume > 0.8ml. It is concluded that enhanced contraction of the antrum can activate vagal afferents signaling to the central nervous system.