A biocidal and photoluminescent treatment of viscose fibre immediately following the addition of carbon disulfide in the conversion of cellulose into viscose (xanthation), which comprises a biocidal composition and an additive that allows the presence thereof to be identified by a luminescent effect, wherein the biocidal composition is added in an amount of 0.1-5 wt % of the material and comprises 3-5% phosphate glass with silver, 1-3.5% silicone, 0.1-0.3% aliphatic hydrocarbons and 90-95% water, and the luminescent additive is added in an amount of 0.1-5 wt % of the material and comprises 20-40% silica gel, 10-30% alumina gel, 30-50% calcium fluoride, 0.5-3% erbium (III) fluoride, 5-15% ytterbium (III) fluoride, a maximum of 5% thulium (III) fluoride and a maximum of 1% europium (III) fluoride, with respect to the total weight of the luminescent additive.