Last three decades, the inverted-T beams have been used as an innovative structural system for RC bridges to support precast stringers in transverse direction. Contrary to conventional top loaded beams, inverted-T beams are loaded on the bottom flange. This loading configuration causes hanger failure due to the generation of vertical tensile forces near the bottom of the web. The objective of the present study is to experimentally examine the effectiveness of new strengthening technique using vertical external pre-stressing stainless steel bars to enhance non-ductile failure mechanism in hanger zones of RC inverted-T beams. The behavior of six inverted-T beams strengthened under different levels of pre-stressing is discussed. The value of pre-stressing level significantly affects the behavior of the inverted T- beams in terms of load deflection, cracking pattern, failure mode, cracking and ultimate load, and strains. The experimental results showed that the pre-stressing strengthening technique proved to enhance the non-ductile mechanisms in hanger zones and able to increase in strength up to 74% compared to the control specimen. Finally, a model capable of predicting the capacity of strengthened inverted T-beams was developed and implemented. The model showed good agreement with the experimental results.