Objectives To evaluate the retention and effectiveness of fissure sealants in permanent first molars in a public programme. Methods Sealant retention in permanent first molars was evaluated in 452 children aged 6-8 years in 20 primary schools under the care of the School Oral Health Programme, Kuwait-Forsyth. The sealants were placed using rubber dam or cotton roll isolation, after cleaning with pumice and rubber cup, and 15 seconds etching. Sealant retention was evaluated at one and two years and scored as complete, partial or complete loss of sealant. Caries was scored when sealant was partially or completely lost. Results A total of 2,744 sealants were applied, with 2,324 and 2,288 sealants examined at the end of the first and second year respectively. In two years, 75% of the sealants were completely retained, 2.9% partially lost, 7.3% completely lost, and 14.8% resealed or restored. A small proportion of teeth (0.9%) were carious. Multivariate analyses showed that occlusal surfaces were 2.8 times more likely to retain a sealant than the buccal and palatal pits (95% CI 2.7-3.9, p<0.0001), and maxillary teeth were 1.3 times more likely to retain their sealant than the mandibular teeth (95% CI 1.01-1.5, p=0.04). Maxillary teeth were less likely to be carious (OR=0.6, 95% CI 0.4-0.97), p=0.03) and occlusal surfaces were 2.8 times more likely to be carious (95% CI 1.9-4.3), p<0.0001). No differences in sealant retention (p=0.24) and caries (p=0.19) were seen between teeth isolated using rubberdam or cotton roll. Conclusions Sealant retention was high, and sealants were effective in preventing caries. Key words: Effectiveness, Kuwait, retention, school programmes, sealants