Purpose: To evaluate the microleakage of Cerec 3, IPS e.max Press, and Turkom-Cera inlays cemented with three self-adhesive resin cements. Materials and Methods: Ninety standardized class III MOD cavities were prepared in intact human mandibular third molars. Ceramic inlays were fabricated according to the manufacturer's instructions and were cemented using three self-adhesive resin cements (RelyX Unicem, Smartcem 2, and SpeedCEM). The specimens were stored in distilled water at 37°C for 24 h and subjected to 1000 thermocycles in water between 5°C and 55°C with a dwell time of 30 s. Subsequently, the specimens were subjected to 100,000 cycles of mechanical loading of 50 N at 1.6 Hz in 37°C water. The specimens were immersed in 0.5% basic fuchsine for 24 h and were sectioned using a low-speed diamond blade. The percentage of dye leakage at the tooth/restoration interface was measured and compared by Kruskal-Wallis tests with Bonferonni correction and Mann-Whitney U-tests at a significance level of p 0.05. Results: Microleakage at the RelyX Unicem interface was lower than that with Smartcem 2 and SpeedCEM resin cements (p 0.05). Microleakage of the Turkom-Cera system was higher than Cerec 3 and IPS e.max Press ceramic inlays (p 0.05). Conclusions: Regardless of the ceramic system and self-adhesive resin cement used, dentin margins were associated with higher microleakage than enamel margins. Keywords: microleakage, inlay ceramic systems, resin cements