We propose two new approaches, referred to as the local and remote methods, for measuring electron beam sizes using parametric X-ray radiation. Using the local method, we have carried out a proof-of-principle experiment, and good agreement was obtained with the results of a standard method using a fluorescent screen. For the remote method, we have proposed a scheme to measure beam sizes using a Fresnel zone plate as an X-ray lens. These methods may prove useful for measuring the sizes of electron beams with small emittances or short bunch lengths in recent advanced accelerators.