Abstract: A folding warning marker includes three tubular stays each having first upper ends joined together by torsional coil springs. A flexible, brightly colored and reflective fabric cover is received over the stays. The torsional coil springs bias each adjacent pair of the three stays apart, forming isosceles triangles such that the fabric cover forms a pyramidal configuration. An apex region of the flexible cover is reinforced to withstand the stress induced by the torsional coil springs. Lower ends of each of the tubular stays are received in respective pockets formed on an interior surface adjacent the lower peripheral edge of the fabric cover. The stays may be manually forced into a parallel relation to form a compact closed position of the warning marker for storage and transportation purposes. The warning marker may be retained in the closed position by a securing strap or a storage tube.