<p>In recent years, the study of natural coagulants of plant origin has increased significantly. This study evaluated a natural coagulant derived from tara seed (<i>Caesalpinia spinosa</i>) for drinking water treatment. First, a screening was carried out using a fractional factorial design (2^5–1) with pH and turbidity levels as key factors. Then, a central composite design (CCD) was applied. Experiments were performed on synthetic turbid water (SW) and real samples. Under medium turbidity conditions, optimal performance was achieved with 5.4&#xa0;mL/L (0.523% p/v) of coagulant at pH 7.6, resulting in turbidity and total suspended solids (TSS) removal efficiency of up to 96%. Under high turbidity conditions, turbidity removal of 98% and TSS of 99% was obtained by applying a dosage of 4.3&#xa0;mL/L (0.416% p/v) at pH 7.2. Statistical models exhibited an R² fit of 0.99% and coefficient of variation (CV) of 1%. Jar tests with a real sample (215 NTU and pH 7.24) demonstrated turbidity and total suspended solids removal efficiencies of 98.5% and 98.90%, respectively, with residual turbidity values ​​below the maximum permissible limits described in Peruvian regulations. These results underscore the potential of the <i>Caesalpinia spinosa</i> seed-based coagulant as an efficient alternative in the flocculation coagulation process.</p>