Humeral intracondylar fissure repair in dogs is typically achieved using a 4.5-mm transcondylar screw (TCS). Proper placement can be challenging considering the complex anatomy, width of the implant, and proximity to the joint. This retrospective case series evaluated the accuracy of a 3D-printed patient-specific drill guide (3D-PDG) for TCS placement in cases of humeral intracondylar fissure. Entry point, exit point, and angulation of the implant was planned preoperatively for 11 dogs (16 elbows) using CT and computer-aided design software. A virtual drill guide was created and the 3D-PDG fabricated using a 3D printer; this was used to place 5-mm TCSs. Postoperative CT images were taken to compare planned versus actual screw placement using the drill guide. Mean entry and exit point deviation were 1.3 and 1.8 mm, respectively, and mean maximum screw angulation was 5.2°. There was no intra-articular screw placement. The authors concluded that 3D-PDG is accurate and consistent for placing TCSs in dogs with humeral intracondylar fissure.