Aims and Objectives: This study was carried out to evaluate the effect of artificial aging on the marginal leakage of crowns and the credibility of three different luting cements in preventing marginal percolation. Materials and Methods: Thirty-six extracted intact premolars were selected for the study. Tooth preparation was carried out to receive complete cast crown. Castings were microblasted with 50 μm alumina powder. Group I was cemented with zinc polycarboxylate (Poly-F® Dentsply De Trey GmbH, Konstanz, Germany), Group II with glass ionomer (Fuji I, Fuji I GC Corporation, Tokyo, Japan), and Group III with resin-modified glass ionomer (Fuji II Plus, Fuji II Plus GC Corporation, Tokyo, Japan). The specimens in the subgroup I served as the control group and those in the subgroup II were subjected to thermocycling to simulate the intraoral conditions. They were artificially aged using artificial saliva as a medium of thermocycling, with a temperature variation of 5°C–55°C. All specimens were treated with 0.5% basic fuchsin dye for 24 h. The crowns were then embedded in clear self-cure acrylic resin and sliced buccolingually. The sectioned halves were then placed under the optical vision microscope, and the depth of dye penetration in the proximal region was qualitatively evaluated. Results: The results showed the mean marginal leakage score is highly significant in thermocycled group as compared to that in non-thermocycled group. The results were subjected to one-way analysis of variance and post hoc Tukey test. It was found that artificial aging did have an effect on the marginal leakage of zinc polycarboxylate group and glass ionomer group. The resin-modified glass ionomer group, however, did not show much significant difference. Conclusion: The artificial aging did have an effect on the marginal leakage of polycarboxylate group and glass ionomer group, whereas resin-modified glass ionomer group did not show much statistical significance. Zinc polycarboxylate cement had maximum micro-leakage followed by glass ionomer cement. Resin-modified glass ionomer showed minimum leakage and can be regarded as the best cement for clinical use.