The aim of this study was to assess oral malodor in highly caries-active children aged 7-15 years, analyze its association with oral malodor parameters, and investigate whether oral hygiene practices and orodental treatments can decrease the effect of oral malodor. The study included a total of 30 subjects with high caries activity (11 boys and 19 girls), mean age 10.5 +/- 2.4 years, who were living in Kirikkale, Middle Anatolia, Turkey. Oral malodor assessment was carried out by portable sulfide monitor and organoleptic method. A self-administered structured questionnaire was given to the participants. The baseline and final measurements were taken for both malodor-related parameters (volatile sulfur compounds [VSCs] and organoleptic ratings) and dental parameters (tongue coating scores [TCS], plaque index [PI], dental index [DFS+DMFS], community periodontal index of treatment needs [CPITN]). Analysis included frequency, cross-tabulations, analysis of variance, independent-samples t test,and paired t test. Odds ratios of VSC-related factors were also calculated. Significance was set at the 5% level. Gender, DFS+DMFS, and frequency of toothbrushing were not found to be significantly correlated with either VSC levels in mouth air or organoleptic ratings (P > .05). However, tongue coating (P = .003), CPITN (P = .014), PI (P = .017), and age (P = .053) were significantly correlated with VSC levels in mouth air. Regarding the final recordings, significant correlation (P < .001) was found between VSC levels and TCS. Also, significant differences were found between baseline and final measurements in both oral malodor parameters and dental parameters (TCS, CPITN, and PI; P < .001). These results revealed that oral malodor in children is related to periodontal parameters and especially tongue coating. Moreover, malodor parameters were improved by increased awareness of the importance of oral hygiene.