School Dental Service is the main oral health programme established to provide curative and preventive oral health care to children of ages 3 to 13 years in Sri Lanka. The information generated through the management information system is hence imperative to describe the oral health status of the children, resource allocation and for rational decision, making at all levels of the school dental service. The purpose of this study was to explore the challenges to quality of data generated at the patient-provider interface of the management information system of the School Dental Service in the Western Province of Sri Lanka. A qualitative exploratory study with School Dental Therapists was conducted, in the form of in-depth interviews. Twelve out of 101 school dental therapists were purposively selected and semi structured interviews were conducted in the last quarter of 2019, until the data saturation was achieved. A thematic analysis was performed to achieve the results. According to the results, the challenges to the quality of data generated at the patent provider interface of school dental service could be explained under three thematic areas. The issues related to reporting system and records, the working environment and the personal perceptions on data collection were the emerged areas of constrains to the data quality in the school dental service in the Western Province of Sri Lanka. The quality of data in the Management Information System of School dental Service could be further enhanced by addressing the issues identified under the key thematic areas at the patient provider interface.