The diagnostics of the physicochemical treatment and electrocoagulation plant of the cardboard packaging company showed that currently, the wastewater has a COD of 18,000 mg/L and suspended solids of 2425 mg/L, therefore, it does not comply with the maximum permissible limits stipulated in nom-001-semarnat-1996. It was found that the physicochemical treatment has a removal efficiency of 33% for COD and 58% of total solids; while the electrocoagulation stage has a negligible effect. In the physicochemical treatment tests, a removal of 92% of the COD was obtained and in the treatment by electrocoagulation, a removal of 37.5% of the residual COD from the previous stage was achieved. This information shows that both treatments can be viable alone or in combination. Objectives: Evaluate the physicochemical treatment and electrocoagulation of wastewater of a company that produces cardboard packaging. Methodology: 1. Develop characterization of wastewater, 2. Develop treatability tests through physicochemical treatment, 3. Develop treatability tests by electrocoagulation treatment, 3. Analyze results. Contribution: This project allowed to know the efficiencies of COD removal, which can be had with the physicochemical treatment, with the treatment by electrocoagulation and with the combined treatment; as well as their optimal conditions in each case. This made it possible to generate operating proposals, which allow reducing operating costs and increasing treatment efficiency.