The aim of the study was to evaluate the effect of curing modes on the cervical microleakage of snowplow restorations done with two different types of composite. Materials and methods: Standardized Class II box only cavities were prepared on either of the proximal surfaces of forty intact extracted. All samples were randomly divided into four groups (n = 10). Group 1 Tetric N ceram continuous polymerization (TNC CP): teeth were restored with snowplow procedure using Tetric N cerem (Ivoclar–Vivadent) and Tetric N flow and cured with continuous polynerization for 15 s; Group 2 (TNC SSP): restorations done same as Group 1 but cured with soft start polymerization for 20 s; Group 3 (Beautifil CP): teeth were restored with snowplow procedure using Beautifil II (Shofu, Kyoto, Japan) and Beautifil II Flow 02 (Shofu, Kyoto, Japan) and cured for 15 s; Group 4 (Beautifil SSP): restorations done same as Group 3 but cured with soft start polymerization for 20 s. After staining with 2% methylene blue solution, each tooth was sectioned mesiodistally with diamond disc and examined under stereomicroscope (Magnification 4 × 40) (Lawrance and Mayo) for the evaluation of dye infiltration. The extent of microleakage was scored using the ISO microleakage scoring system. Results: TNC SSP group showed significantly less microleakage than TNC CP group. Between Beautifil CP and Beautiful SSPs, there was no significant difference in the microleakage. Conclusion: Soft start polymerization significantly reduced the microleakage in snowplow restorations done with TNC composite, but it is insignificant in the Beautifil II composite