Objectives: The aim of this retrospective study was to analyze the occurrence and characteristics of pre-eruptive intracoronal resorptions in a clinical orthodontic patient population. Materials and methods: Patients treated in an orthodontic department (University of Pe & PRIME;cs, Pe & PRIME;cs, Hungary) were included. Unerupted teeth on panoramic radiographs were analyzed for intra-coronal radiolucent lesions. For each patient, the demographic data, jaw localization, number of unerupted teeth with pre-eruptive intracoronal resorption lesions, number of lesions per tooth, size and localization of pre-eruptive intracoronal resorption defects, affected tooth's surface, pulp involvement and ectopic position of the tooth with defects were recorded. Results: In the 3,143 patients investigated, 55 teeth in 49 patients showed pre-eruptive intra-coronal resorption lesions (subject incidence: 1.56%). The incidence on unerupted teeth was 0.25%. Pre-eruptive intracoronal resorption was significantly more common in mandibles (43 mandibular vs. 12 maxillary lesions) with an odds ratio of 12.84 (95% Confidence Interval: 5.19-31.74) and no gender differences were found (p = 0.746). The occurrence of pre-eruptive intracoronal resorption was highest in the youngest (7-10 years) mixed dentition status group (p < 0.001). Most of the lesions (44 of 55, or 80.0%) were localized in the dentin, occupying two-third or less of the dentin thickness. Only 12.73% (7/55) of the lesions were not localized on the occlusal surface. Of the lesions, 89.1% (49/55) showed no obvious size increase over an average follow-up of 36.4 & PLUSMN; 8.1 months. Conclusions: Pre-eruptive intracoronal resorption may occur mainly in the mixed dentition stage in orthodontic patients. Careful and attentive radiographic evaluations may facilitate early detection and follow-up of the lesions' possible dimensional changes, especially when resorption influences orthodontic extraction therapy.