Dental caries the most common chronic childhood disease is the primary cause of tooth loss.In spite of considerable improvement in the dental health of children, the incidence of decayed fissures in the first permanent molars is still high. Caries in pits and fissures has responded less to routine preventive methods than caries on smooth surfaces.Special preventive efforts are needed if further caries reduction is to be obtained.Application of fissure sealants and fluoride varnishes are two preventive procedures for dental caries developed since the 1960's .This study compares the effectiveness of fissure sealant and fluoride varnish in prevention of occlusal caries.