Statement of Problem: Base metals are still widely used in dentistry. However, biological and aesthetic disadvantages related to base metal alloy supported restorations are reported. There are not enough studies about surface coating processes that improve the mechanical, aesthetic and biological properties of the surface they are applied to. Purpose: The purpose of this study was to evaluate the effect of surface coatings of metal frameworks on early and long-term bond strength and microleakage at metal-ceramic interfaces. Material and Methods: A total of 72 metal frameworks were abraded with 50-µm aluminum oxide (Al2O3) particles and randomly divided into three main groups (n=24). Group C: no coating was applied (Control); Group TN: specimens were coated by titanium nitride; Group TAN: specimens were coated by titanium aluminum nitride. Surface morphology was examined under a Scanning Electron Microscope (SEM). Veneering porcelain was applied to all metal frameworks. Half of the specimens in each group were subjected to an early bond strength test. The remaining specimens were subjected to early microleakage analysis, thermocycled for 6,000 cycles, and thereafter subjected to long-term microleakage analysis and a bond strength test, respectively. Data were statistically analyzed by a one-way Analysis of Variance (ANOVA), independent-samples t-test, and pairedsamples t-test (a=0.05). Results: The group TN showed significantly higher values in the early flexural bond strength test, but no significant difference (P=0.068) was found among the groups in the long-term test results. In early microleakage analysis, no significant difference (P=0.481) was found among the groups, whereas the group TN was significantly different (P< 0.001) from other groups in the long-term analysis. Conclusions: Both surface coating methods have shown no superior microleakage results compared with the control group in early and long-term analyses. Titanium Nitride (TiN) and Titanium Aluminum Nitride ((Ti,Al)N) coating of metal frameworks are not effective methods to increase porcelain bond strength.