Aim: The present in vitro study aimed to evaluate the transverse strength of heat cure acrylic denture base resins repaired with three different joint surface designs, repair material being the glass-fiber-reinforced self-cure repair material along with surface pretreatment. Materials and methods: A total of 40 heat cure resin specimens were fabricated and finished to a size of 64 mm × 10 mm × 2.5 mm. These specimens were divided into four groups of 10 each, with butt, round, and bevel repair surface joints, respectively, along with the control group. After the specimens were cut in the middle for the repair procedure to proceed, the aforementioned joint surface contours were prepared for groups I, II, and III, respectively, treated with dimethyl chloride for 30 seconds, and the repair was done with E-glass-fiber-reinforced self-cure repair material. Results: The mean transverse strength of the control group was 100.37 N, which was highest (significant p value of <0.05), followed by group III (bevel joint) 54.23 N, group I (butt joint) 53.93 N, and group II (round joint) 44.55 N. Conclusion: Distribution of stresses evenly in the repair region will be achieved by the proper selection of the joint surface contour, and this study showed that the 45° bevel joint was an appropriate selection along with promising repair material and surface pretreatment. Clinical significance: Clinically, in the event of repairing a broken denture, a rapid and economically convenient material with superior physical and mechanical properties is important to maintain the adequate transverse strength of the repaired denture. Glass-fiber-reinforced autopolymerizing resin, with a 45° bevel joint design of the broken surfaces and surface pretreatment proved to reduce stress concentration, improving the transverse strength of the repaired heat cure denture base resins.