Introduction: Child Oral Impact on Daily Performance Index (C-OIDP) assesses the impact of oral health problems on children's daily activities. Objective: The study examines the correlation between Oral Health-Related Quality of Life (OHRQoL) and dental status among schoolchildren in a non-urban region of south-western Tanzania. Material and Methods: The clinical trial was carried out among school children in Ilembula. A Kiswahili version of the C-OIDP inventory was completed. Further, an oral examination was carried out, in which a mirror, dental probe, and flashlight were used to determine the caries prevalence and the oral hygiene. Results: 162 schoolchildren participated in the study (70 female, 92 male, age 12.30 ± 0.57 years, range 12-14 years). 96.30% of the subjects had experienced one problem with their mouths or teeth within the last 3 months. In 23.08% physiological dentition was the most common problem. 11.04% of the children complained about toothaches during this period. 66.03% had had one daily performance affected by their oral condition. The generic OIDP index differentiated between the proportion of subjects with (DMF/T > 0) or without (DMF/T = 0) carious lesions and with (Simplified Oral Hygiene Index [OHI-S] > 0) or without periodontal problems (OHI-S ≤ 1). Conclusion: C-OIDP index indicates a correlation between clinical oral health and the subjectively perceived impairment of the quality of life. An OHRQoL trial applying C-OIDP is a useful and important tool giving a comprehensive picture of the oral health situation in Ilembula. Further studies should document the course over several years. Keywords: Child Oral Impact on Daily Performance Index, Oral Health Related Quality of Life caries incidence, Tanzania, epidemiology