Purpose: This study evaluated sealants placed on permanent molars in first-grade students in Shiraz primary schools during 2008 under a school oral health programme. Materials and Methods: A total of 420 sealed first permanent molar teeth in 179 students (mean age 8 years, 6 months) were evaluated for fissure sealant retention, occlusal caries status and Feigal criteria. All teeth were examined 1.5 years after application. The fissure sealants (Conceal F, SDI) were placed on occlusal surfaces after traditional acid etching. Statistical analysis was done with the chi-square test (P 0.05). Results: 57.5% of the seals were completely retained, 29.6% partially lost and 12.9% completely lost. There were no signs of carious lesions in 77.1% of the teeth. According to the Feigal criteria, success rates based on marginal integrity, marginal discolouration and anatomical form were 98.2%, 95.5% and 58.6%, respectively. The overall success rate with all three criteria was 54.14%. There were no significant relationships between the results and patient gender or tooth position in the arch. Conclusion: Although fissure sealants are an effective method for preventing tooth caries, the results of this study indicate that public oral health programmes need to be implemented more carefully and that follow-up programmes are advisable. Keywords: caries prevention, community dentistry, pit and fissure sealant, preventive dentistry, public health dentistry