The increased use of synthetic textiles, particularly polyester, raised environmental concerns due to the release of microplastic fibres during domestic laundering activities. This study focuses on the effect of surface treatments on the microplastic fibre release behaviour of polyester fabrics after multiple washing cycles. Five fabric types were tested: untreated (raw) polyester and four pre-treated samples with 0.6% and 1.2% sodium hydroxide (NaOH) and chitosan solutions. Washing trials were conducted in accordance with ISO 4484-1:2023 protocol. Filtration and drying processes are carried out after the first, third, and fifth washes. Quantification is made by assessing the mass and count data of microplastic fibres collected on glass fibre filters.