The objective of this split-mouth randomized controlled trial was to compare clinical retention rate of Thailand innovative clear sealant (LAS-clear) and imported sealant (Delton clear: Dentsply International, Inc., USA). This study was comprised 120 pairs of contralateral first permanent molars of 64 children aged 6-9 years old. The retention of the sealant was investigated at 6- and 12- month post-treatment with evaluation criteria: 1) total retention, 2) partial loss, and 3) total loss. The data were collected and analyzed using McNemar’s test at p = 0.05. Our results demonstrated that the retention on occlusal surface of LAS-clear group has the total retention at 81.0% and 71.1% at 6- and 12-month post-treatment, respectively, while that of Delton clear group was 80.0% and 66.3% at 6- and 12-month follow-up, respectively. No significant difference between the two groups at 6- and 12- month follow up was observed (p = 1.0 and 0.54, respectively). In conclusion, the retention rate of Thailand innovation LAS-clear is equal to Delton clear sealant at 12 months follow-up.