The decolourisation of two different bio-treated real textile wastewaters (TWA and TWB) was evaluated through a photochemical UVC/H2O2 oxidation system. The photochemical experiments were performed in a lab-scale tubular photoreactor, where a borosilicate tube is associated to an internal concentric quartz tube containing a UVC lamp (6W) allocated in the focus of two stainless steel reflectors. The reaction rate was evaluated under different operating conditions: H2O2 dosage (0-40 mM), pH (3, 5 and 9) and temperature (15, 23 and 35 °C). The biodegradable organic fraction increased for values higher than 40% (Zahn-Wellens test). Both wastewaters achieved the colour discharge limits imposed by the Brazilian regulations after 180/75 min of UVC irradiation (8.3/3.4 kJUVC L-1) using an H2O2 dose of 25 mM, at natural pH (7.7/8.1) and T = 23 °C.