Purpose: To investigate the effect of multiple firing cycles on shear bond strength and failure mode of porcelain fused to metal. Materials and method: Sixty porcelain fused to metal discs were divided into four groups according to number of firing cycles subjected to; group A; one firing cycle, group B; two firing cycles, group C; three firing cycles and group D; four firing cycles to sinter the porcelain. All the specimens were thermocycled for 300 cycles then collected, labeled and stored in distilled water for 48 hours before testing. Shearing test was done by compressive load applied using a mono-bevelled chisel shaped metallic rod attached to the upper movable compartment of testing machine traveling at cross-head speed of 0.5 mm/ min. Fractured specimens were ultrasonically cleaned, carefully checked under digital microscope (Dino-Lite, 241 Taiwan). All failures mode were analyzed. Results: The highest mean value was observed in group A (21.62 MPa) and the lowest mean value was observed for group B (19.29 MPa). Statistical analysis revealed no significant difference between groups (P= 0.644). Statistical analysis among groups showed no significant differences either. Conclusion: Repeated firing cycles up to four cycles had no significant effect on shear bond strength of porcelain fused to metal. Regarding failure mode; all samples had mixed (cohesive adhesive) failure. Keywords: Shear bond strength, Firing cycles, PFM, MCR, Porcelain and Metal.