One of many possible complications of cancer therapy in children is enamel demineralization and such changes in the ion content of dental hard tissues may increase susceptibility to caries. The study aims to assess the prevalence of dental caries among childhood cancer survivors.A cross-sectional study was conducted on 225 children aged between 4 and 18 years, including 75 cancer patients and 150 sex- and age-matched controls. The cancer survivors were recruited from single pediatric oncology center. The control group was formed from students of randomly selected kindergartens and schools. Dental investigation was held between July 2013 and January 2016, approximately 5 years after the cessation of anticancer treatment (range: 6-155 months). The occurrence of dental caries was assessed with DMF/dmf index (showing the mean number of decayed, missing and filled permanent/deciduous teeth). Univariate statistical approach was performed and P-values < .05 were considered as statistically significant.The frequency of dental caries was comparable in both groups (85.4% vs 84%). However, the DMF index was higher in cancer patients than in controls: the median and interquartile ranges were 2 (0-4) vs 0 (0-2); P < .01. This correlates with duration of anticancer therapy (r = 0.26; P < .05). Moreover, children who had radiotherapy of the head and neck regions had significantly higher DMF scores than the ones who did not: 4.5 (1-6) vs 2 (0-4); P < .05. Socioeconomic and education status within family also has a significant impact on DMF scores in the cancer group. In conclusion, cancer patients, particularly those with a poor social background, should receive professional dental care as their caries process is more active than that of healthy peers.