BACKGROUND: Vertical bitewing radiographs (VBWs) are often used in paediatric dentistry but no clinical studies have been conducted to evaluate the feasibility or effectiveness of their use. HYPOTHESIS/AIM: To evaluate the quality of VBWs taken in children by undergraduate dental students. DESIGN: VBWs were taken for high-caries-risk children using two types of vertical holders: Snap-A-Ray and Red Rinn XCP. Trained and calibrated examiners assessed VBW quality including positioning errors, visibility of crown and furcation area of primary molars and presence of permanent successor. Association between VBW quality scores and independent variables was investigated using ordinal logistic regression (α = 5%). RESULTS: A total of 150 VBWs were evaluated. Radiographs were rated as excellent (10.67%), diagnostically acceptable (72%) and diagnostically compromised (17.33%). VBWs allowed the visualisation of the entire primary molar crown (80.55%), furcation (90.54%) and permanent successors (86.37%). Common positioning errors included horizontal errors (48.67%) and coning off (38.67%). Use of the Red Rinn XCP holder was significantly associated with improved VBW quality compared to Snap-A-Ray (p = 0.045). CONCLUSIONS: The use of vertical bitewings allowed visualisation of the primary molars crown, furcation area and presence of permanent successors. The use of a Red Rinn vertical holder can improve the quality of the bitewing radiographs by avoiding positioning errors.