Introduction: Temporary restorations are very important in fixed prosthodontic rehabilitation, especially when long-term treatment is needed. Aim: This study aimed to compare the vertical marginal gap of temporary bridges constructed by CAD/CAM, 3D printing and conventional method. Material and methods: The mandibular right second premolar and second molar of a dentoform acrylic resin cast was prepared to receive full coverage fixed partial denture. The model was scanned with Ceramill Map 400 optical scanner. A STL file was transferred to Ceramill motion 2 milling machine to mill twenty-one working models. One model was scanned by In Eos X5 scanner and twenty one standardized full contour temporary bridges were constructed by three different techniques. The bridges (n=21) were grouped into three groups (n=7); group A (CAD/CAM), group B (3D printing ) and group C (Conventional). The retainers marginal gaps were measured using a digital stereomicroscope. Bridges were cemented using Temp Bond NE cement then their vertical marginal gaps were remeasured. Data were analyzed by one way ANOVA and Post Hoc Tests at p≤0.05.  Results: The highest mean value was reported with the conventional samples (120.42±6.95 μm) and the lowest value was reported with the 3D printed samples (68.98±9.93 μm) before cementation, while after cementation the highest mean value was reported with the conventional samples (216.6±14.15 μm) and no statistically significant difference between the 3D printed samples and CAD/CAM samples. Data were analyzed by one way ANOVA and Post Hoc Tests at p ≤ 0.05. Conclusion: The method of fabrication of temporary bridges had an effect on the vertical marginal gap.