Abstract: A protective vent line cap for protecting sanitary plumbing vent lines is described. The vent line cap includes an open bottom conically flared shroud that attaches to the vent line using a mounting strap having an adjustable strap clamp fastener and a mounting bracket. The mounting bracket is fastened at its top to the shroud and at the bottom to the strap clamp. The vent line cap is designed to be easily installed and removed using common hand tools. The vent line cap prevents foreign material from entering the vent line and subjacent plumbing while still allowing air to flow from the vent line as well as preventing rain water from entering sewer system.