A new nondestructive inspection method for fiberglass-reinforced plastic mortar (FRPM) pipes using microwave and photonic techniques is proposed. A FRPM pipe has been widely used for water pipelines and electrical cable protection tubes since it shows high mechanical strength and high corrosion resistance despite being light weight. However, nondestructive inspection method for FRPM has not been established as far as we know. Recently, we found that a FRPM pipe of 250-1000 mm in diameter and 18 mm in thickness can be a good cylindrical waveguide with single or a few TE/TM guided modes for 1-6 GHz microwave and that the microwave transmission along a FRPM pipe is rather affected by defects in the FRPM pipe or its surface condition. With accurate measurement of a transmitted microwave signal using an electro-optic sensor, we can detect a defect or crack in a FRPM pipe nondestructively.