Small gradients are ideal in performance. Vertical-field MRI systems use biplanar gradient coils, and the coil sizes are no smaller than the magnet gap. Here we propose the oval geometry for gradient coils for vertical-field MRI to increase coil performance, Oval coils could be smaller than biplanar coils with maintaining the high accessibility and gradient linearity. Moreover, oval coils are preferable from the viewpoint of heating problems, because the gradient heat is efficiently cooled by air. In this study, we designed and constructed oval gradient coils for a 0.3 T, open MR scanner, and demonstrated the validity of the concept.