The TG/DTG analysis of the raw cotton-flax fabric (40% flax-60% cotton), bioscoured samples with/without ultrasonication (in the presence of different enzyme concentration and action time) and of the alkaline treated sample has been achieved aiming to study the influence of the experimental conditions on the pectin elimination and quantifying the efficiency of the eco-friendly process. TG/DTG results were correlated with FT-IR data. Even at a short action enzyme time the results demonstrate the efficacy of the ultrasonication in the ecofriendly scouring process, which becomes more pronounced as the enzyme concentration and action time increases.