PurposeThe present study aimed to determine the prevalence of self-reported oral problems and the oral health–related quality of life (OHRQoL) in childhood cancer survivors (CCS).MethodsPatient and treatment characteristics of CCS have been collected in a cross-sectional study, part of the multidisciplinary DCCSS-LATER 2 Study. To assess self-reported oral health problems and dental problems, CCS filled out the ‘Toegepast-Natuurwetenschappelijk Onderzoek’ (TNO) oral health questionnaire. OHRQoL was assessed by the Dutch version of the Oral Health Impact Profile-14 (OHIP-14). Prevalences were compared with two comparison groups from the literature. Univariable and multivariable analyses were performed.ResultsA total of 249 CCS participated in our study. The OHIP-14 total score had a mean value of 1.94 (sd 4.39), with a median score of 0 (range 0–29). The oral problems ‘oral blisters/aphthae’ (25.9%) and ‘bad odor/halitosis’ (23.3%) were significantly more often reported in CCS than in comparison groups (12% and 12%, respectively). The OHIP-14 score was significantly correlated with the number of self-reported oral health problems (r= .333,p<0.0005) and dental problems (r= .392,p<0.0005). In multivariable analysis, CCS with a shorter time since diagnosis (10-19 years vs. ≥30 years) had a 1.47-fold higher risk of ≥1 oral health problem.ConclusionThough the perceived oral health is relatively good, oral complications following childhood cancer treatment are prevalent in CCS. This underlines that attention to impaired oral health and awareness on this topic is mandatory and regular visits to the dentist should be a part of long-term follow-up care.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00520-023-07797-1.