Dental caries among preschool children is common but there is scarcity of updated data about its prevalence among Nepalese preschool children. This study was conducted to evaluate prevalence, Significant Caries Index, Caries pattern, Restorative care index and Disparity ratio among preschool children of Kathmandu aged 3-6 years. A cross sectional study was conducted on 17 preschools of Kathmandu following WHO criteria. Data were analysed using SPSS 20 and descriptive statistics was applied. Prevalence of dental caries was 803 (55.6%) with a mean deft of 3.28±3.581 and Significant Caries Index score was 7.439. Caries pattern showed the most commonly decayed teeth were mandibular second molars followed by maxillary central incisors. The least affected teeth were mandibular lateral incisors. The restorative care index was 106 (7.32%) in the total sample size and 14 (2.86%) in the SiC and disparity ratio was 2.26. The SiC Index indicated high dental caries prevalence; severity rates and restorative care index indicated little experience of restorative treatment in preschool children of Kathmandu identifying the need for more targeted efforts to reach preschool children early to effectively address unmet oral health needs.