Background <p>This in vitro study assessed the influence of using two types of fiber-reinforced composite with different placement methods on the flexural strength of two resin materials.</p> Methods <p>Specimens were fabricated using two FRC products (QUARTZ SPLINT^® UD(UD) / WOVEN (WO)) with two resin composites (BEAUTIFIL II (BT II) and BEAUTIFIL Flow Plus (BF+)). Seven placements were employed to prepare specimens for each composite, including one control group without FRCs, two using UD, and the other four using WO. Specimens were prepared for flexural strength testing to evaluate the mechanical properties. Fracture mode was examined by dividing it into three categories. Three-way ANOVA and Tucky’ HSD test was performed (<i>α</i> = 0.05), with macro images and scanning electron microscope (SEM) micrographs analyzed.</p> Results <p>In comparison to the control group, experimental groups utilizing BEAUTIFIL II (BT II) and BEAUTIFIL Flow Plus (BF+) with FRCs showed higher flexural strength (116.80 ± 11.45&#xa0;MPa/107.02 ± 13.68&#xa0;MPa and 302.06 ± 89.00&#xa0;MPa/358.16 ± 96.10&#xa0;MPa, respectively) (<i>p</i> &lt; 0.05). Three-way ANOVA revealed that the flexural strength values were significantly affected by different resin composites, placing methods and fiber orientation respectively (<i>p</i> &lt; 0.001).</p> Conclusions <p>FRCs can be used as a reinforcing material for resin composites in a simulation of direct restoration. In some situations, the use of FRCs avoided complete fracture. The placement of FRCs and the composite used could be considered when applied clinically.</p> Clinical trial number <p>Not applicable.</p>