Objectives <p>To evaluate the influence of the number of periapical radiographs with different vertical angles of the X-ray beam and the impact of digital enhancement filters on the diagnosis of horizontal root fracture (HRF).</p> Methods <p>Twenty-four single-rooted teeth, 12 with HRF and 12 without HRF, composed the sample. For the first evaluation, periapical radiographs of the teeth were acquired individually with the VistaScan^® system, using three vertical angulations of the X-ray beam (orthoradial, plus 15°, and minus 15°), which were arranged in different image files containing one, two, or three radiographs with different angulations of the same tooth. For the second evaluation, six image enhancement filters from the DBSWIN^® software were applied to the orthoradial radiographs. For all evaluations, five examiners verified the presence of HRF using a 5-point scale. Weighted kappa was used to calculate intra- and inter-examiner reproducibility. Diagnostic values were compared between the conditions by one-way ANOVA (<i>α</i> = 0.05).</p> Results <p>The area under the receiver operator curve, sensitivity, and negative predictive values were lower when HRF was diagnosed with only one radiograph (<i>p</i> &lt; 0.05) compared to two or three radiographs, which did not differ among themselves (<i>p</i> &gt; 0.05). There were no differences between the images evaluated in different filter conditions (<i>p</i> &gt; 0.05). Intra- and inter-examiner agreement ranged from moderate to almost perfect and fair to substantial, respectively.</p> Conclusions <p>Evaluation of two radiographs with different vertical angulations improves the diagnosis of HRF and is recommended. The use of VistaScan^® system image enhancement filters does not influence this diagnosis.</p>