Wastewater effluent from the textile industry is known for its diverse pollutant loads. Conventional physicochemical technologies face limitations in effectively removing these contaminants from textile wastewater due to issues such as high energy consumption, long processing units, generation of toxic byproducts, and high cost. In this work, the performance of a sequential anaerobic-aerobic (SA-A) treatment process was evaluated for real textile wastewater, utilizing enriched dye-degrading microorganisms as an inoculum. The experiment involved four phases (Phases I, II, III, and IV) with corresponding organic loading rates (OLRs) of 0.5, 1.0, 1.5, and 2.0 g COD/L.day to access the biodegradation of the textile wastewater. The system’s performance was evaluated based on the removal efficiency of color, COD, TKN, NH4+-N, NO3-N, SO42-, PO43, and pH stability. Biodegradation was further studied using UV‒visible spectra and FTIR analysis. Results showed that the SA-A treatment process achieved a maximum color removal of 95.6% and COD removal of 87.6% during Phase III (OLR of 1.5 g COD/L.day). Phase II (1.0 g COD/L.day of OLR) exhibited the highest removal efficiencies for TKN (70.7%) and phosphate (55.2%). These improved removal efficiencies were attributed to increased biomass of the system. The anaerobic stage showed a significant color and COD removal; accounting for over 65% of COD and 90% of color removal. The aerobic stage was responsible for high TKN (62%) and phosphate (51%) removal. However, the aerobic stage was led to an increase in NO3-N concentration, requiring further treatment to prevent eutrophication. Moreover, sulfate removal did not show a remarkable change in this study. Additionally, the SA-A treatment process demonstrated consistent performance when applied to wastewater with varying characteristics. UV-visible spectra and FTIR analysis of influents and effluents reveled significant changes, indicating alterations in the structure parent dyes. Overall, this study highlights that the SA-A process can help textile industries meet their stringent environmental legislation and improve the efficiency of their water treatment systems. Key words; Textile wastewater, color removal, anaerobic-aerobic treatment, organic loading