Aim: The aim of the study is to determine and compare the microleakage and marginal adaptation of three different glass ionomer cements in class v cavity using scanning electron microscopy analysis. Materials and methods: In class V cavities, three distinct glass ionomer cements were evaluated for marginal adaptability in vitro. Groups 1 through 4 include Fuji Ix (Control), Zirconomer Improved, Riva Self Cure, and Xtracem-S. In this investigation, 40 recently extracted single-rooted human mandibular premolars were employed. Class V cavity measuring 3 mm broad mesio-distally, 2 mm wide occluso-gingivally, and 1.5 mm deep was constructed on the buccal and lingual sides of each tooth. The chosen samples were prepared with class V cavities repaired and randomly assigned to four groups of ten teeth each. The reconstructed teeth underwent thermocycling, and the restoration's center was longitudinally sectioned in a bucco-lingual orientation. After that, these sections were inspected at a 1000x magnification using a scanning electron microscope. Results: Values from the marginal gap measurement were tallied and subjected to statistical analysis. Out of the four glass ionomer cements, Xtracem-S (GROUP 4) demonstrated the least microleakage at the significant level (p<0.01), followed by Fuji IX (GROUP 1), Riva self-cure (GROUP 3), and Zirconomer improved (GROUP 2). Fuji IX had the highest microleakage (CONTROL GROUP). Conclusion: Riva self-cure (GROUP 3) and Xtracem-S (GROUP 4) demonstrated comparatively less microleakage in this investigation. Zirconomer Improved (GROUP 2) and Fuji IX (GROUP 1) had the highest comparable microleakage.