Look for leaves that are attached to a vine that is growing upward rather than outward. Grapevines do not grow along the ground, but rather will grow upward and wrap around objects such as trees. If you see vines with leaves growing along the ground, it is most likely an ivy and not a grape leaf.
Search for leaves that are a uniform green color and that are a heart shape or three-lobed shape. Grape leaves often resemble a maple leaf, except that they are larger, reaching six to eight inches wide.
Examine the edges of the leaf for an irregular jagged edge. Grape leaves have several shapes, but all have a jagged appearance around the edge of the leaf.
Look for leaves that have short, tiny hair-like projections on the underside of the leaves as well as along the stem of the leaves. While not all grapevine have these tiny hairs, most of the them do.
Examine the base of the leaves and look for thin, curly tendrils of vine. Grape leaves all have these small tendrils near them, which distinguishes them from other types of leaves.