A portable gate assembly for use in combination with a corral or holding pen to capture wild or renegade cows is disclosed. The portable gate assembly includes a frame defining a frame opening extending therethrough, the frame opening being sized such that the cow sought to be captured can pass therethrough. A gate is pivotally connected to the frame such that the gate is selectively movable between a first position and a second position. In the first position the gate is positioned in at least a portion of the frame opening such that the lower end of the gate is disposed a distance above the ground to permit at least a portion of the cows head to the position thereunder, in the second position the gate being moved inwardly and upwardly into the corral or holding pen and over the back of the cow when the cow moves through the frame opening and into the corral or holding pen. To prevent the cow from escaping, once captured, the portable gate assembly further includes at least one stop member connected to at least one of the frame and the gate for preventing outward movement of the gate and thereby escape of the captured cow through the frame opening.