Calcium lignosulfonate (CLS) (C20H24CaO10S2) is widely used in various industries today, including wood, construction, food, agriculture, and textiles. It has been noted that there are currently few studies on the addition of CLS chemicals to various fiberboards. This study was designed to explore the outcomes of the interaction between CLS and the boards, with the aim of expanding the potential applications of this chemical. In this study, we incorporated CLS at varying percentages (6%, 8%, and 10%) as an adhesive additive in high-density fiberboard (HDF) produced using urea-formaldehyde (UF) resin in a laboratory setting. We assessed its impact on several physical properties [thickness swelling (TS), density, and water absorption (WA)] and mechanical properties [modulus of rupture (MOR), internal bond strength (IB), modulus of elasticity (MOE), and surface soundness (SS)]. A control group was established using prepared boards, allowing for a comparison of results between boards made with and without CLS additives. According to the results of a multivariate analysis of variance, the CLS percentage showed no significant effect on density, MOE, and SS. However, it significantly influenced TS, WA, IB, and MOR, resulting in reductions of 4-12% for SS, 6-12% for MOR, and 2-22% for IB, while increasing TS by 20-130%, WA by 25-84%, and MOE by 1-3%. It was observed that the use of CLS in the study led to differing results in the tests conducted on the produced HDF materials.