Aim:To evaluate and compare the retention ability, anticaries effect and marginal discoloration when sealed with a glass ionomer-based sealant (Fusion i-seal) and a resin-based fissure sealant (Helioseal-F) on permanent first molars. Materials and methods: Caries free, fully erupted permanent first molars of 50 children between 6 years and 8 years were sealed with pit and fissure sealants under rubber dam isolation. Glass ionomer-based sealant was applied on a permanent first molar and the contralateral molar with resin-based sealant. The sealants were evaluated at regular intervals for a period of 1 year. Statistical analysis was done by Chi-square test. Results: Higher retention rates were noted for resin-based sealant (88%) compared to glass ionomer-based sealant (78%). None of the teeth sealed with resin sealant developed caries whereas 2% of teeth sealed with glass ionomer sealant developed caries. Marginal discoloration was not noted in teeth sealed with glass ionomer sealant whereas slight marginal discoloration was noted for 6% of teeth sealed with resin sealant. Conclusion: Clinically a difference was noted in the retention rate, anticaries effect and marginal discoloration whereas statistically no significant difference was noted for the two sealants after 1 year. Clinical significance: Pit and fissure sealants are highly effective and economical in preventing occlusal caries in young permanent tooth with low failure rate. 554compared with the retention and anticaries properties of a resinbased fissure sealant (Helioseal-F).