Background: Pit-and-fissure sealants are safe and effective ways to prevent dental caries and are considered as a part of an overall caries-preventive strategy. Dental caries are a public health problem and the most common intraoral disease affecting mankind. It is an infectious transmissible disease, with the child patient being at the highest risk. Objectives: The purpose of this study was to evaluate the retention rates and effectiveness of occlusal sealants in children in Hamadan, Iran. Materials and Methods: A total of 118 sealed first permanent molar teeth in 52 students (mean age, 8 years; male, 48%) were evaluated for fissure sealant retention and occlusal caries status. All teeth were examined 12 months after application of sealants. Data were collected and evaluated by survival analyses methods for age at placement, patient sex, decayed/missing/filled teeth (DMFT) index, fluoride history, toothbrush, tooth position in arch, and refer to dentistry. Results: The overall success rate with pit-and-fissure sealant was 68.6%; in addition, 38.9% of the seals were completely retained, 38.9% partially lost, and 10.2% completely lost. There were no signs of carious lesions in 69.6% of the teeth. The factors associated with an increased risk of failure included female sex (P = 0.001) and no history of fluoride use (P < 0.01). There were no significant association between the results and patient age, tooth position in the arch, DMFT index, toothbrush, and refer to dentistry. Conclusions: Although pit-and-fissure sealants are effective methods for preventing tooth caries, the low success rate of fissure sealants in current study indicated that dental sealant need to be implemented more carefully and follow-up programs are advisable.