A weather-resistant monitoring camera has a case, a camera set, a frame, a lens and an adjusting assembly. The case has a body to receive the camera set, the frame, the lens and the adjusting assembly. The frame is used for holding the camera set in place and the camera lens is mounted on the camera set. The adjusted assembly is used for adjusting the lens and is mounted outside the body. Because the camera lens is mounted inside the body and can be adjusted by the external adjusting assembly, rain, wind and a force of shock will not damage the camera lens.