Incorporating GFRP stirrups as shear reinforcement in precast concrete tunnel lining (PCTL) segments is a practical approach to enhance the punching performance of infrastructure projects. Punching loads in tunnels can be induced by the expansion of rock or other geotechnical conditions on their extrados surfaces. This study reports the first-ever experimental investigation on the punching-shear behavior of precast concrete tunnel segments with glass-fiber-reinforced polymer (GFRP) bars as flexural reinforcement and GFRP stirrups as shear reinforcement. Two full-scale PCTL specimens reinforced with the same longitudinal and transverse ratios were fabricated and tested under point loads until failure. A rhomboidal-shaped segment measuring 2100 mm in length and 1500 mm in width with a thickness of 250 mm was used in the experimental program. One of both segments had shear reinforcement using a new arrangement technique to assess its contribution to punching capacity. The results are reported and discussed in terms of general behavior, cracking pattern, reinforcement strains, and mode of failure. The experimental results revealed that both segments exhibited final punching-shear failure with no signs of concrete crushing and a similar crack pattern. However, the segment with shear reinforcement had a higher cracking load, stiffness, and punching capacity. These results indicate that using stirrups in GFRP-reinforced PCTL segments represents a realistic solution for the structural integrity of tunnels where initial cracking and ultimate capacity are the governing criteria.