In situ synthesis of silver nanoparticles on raw cotton fabric was studied for Diploma thesis. Synthesis occurred directly on cotton when it was immersed in precursor solution of silver nitrate and after in water-extracts of food waste plant materials (green tea leaves, avocado seed and pomegranate peel) and invasive alien species (Japanese knotweed rhizome, Staghorn sumac fruit and Goldenrod flowers). For comparison, the cotton fabrics were treated also only with water-extracts. Colour values (CIE L*a*b) and colour depth (K/S values) were determined using a reflectance spectrophotometer. Ultraviolet protective properties of the samples (UPF values) were analysed using UV/VIS spectrophotometer. The morphology of fibres and formed nanoparticles was analysed using scanning electron microscopy (SEM). Silver content was determined using inductively coupled plasma mass spectrometry (ICP-MS). Antibacterial properties of the samples, where in situ synthesis was performed, were also analysed. Different size and content of spherical shaped nanoparticles were formed on fibres using water-extracts as reducing agents. Size and shape of silver nanoparticles influence the reduction of Escherichia coli in Staphylococcus aureus bacteria. The antimicrobial properties were excellent for the samples with synthesized nanoparticles. Furthermore, excellent protection against ultraviolet radiation was determined for the samples without and with formed nanoparticles. After twelve times washing cycles, the samples with silver nanoparticles still show excellent protection against ultraviolet radiation, all other sample were classified with very good or good protection category. The presence of nanoparticles on cotton also influences its colour, which is darker, with reddish and yellowish hue. Most of the samples become lighter and bluish after repetitive washings.