In recent years, there has been increasing public concern about ultraviolet radiation (UVR), and clothing is considered to provide the most effective protection against it. In this study, the influence of aging and UVR on the antibacterial properties and degree of coloration of knitted fabrics was investigated. Knitted fabrics of different raw materials compositions in single weaves made of three types of yarn: cotton (CO), bamboo (BAM), and polyester (PES), were used. Samples were treated with methanol extract of Achillea millefolium L. conc. 100 mg/mL, to which citric acid and tannic acid were added, using ultrasonic atomization. Using an ultrasonic atomizer increased the speed of dyeing, shortened the processing time and allowed the use of a smaller amount of extract compared to conventional dyeing. The antibacterial properties of knitted fabrics obtained against Staphylococcus aureus and Escherichia coli were evaluated. The tests of antibacterial properties and color strenght (K/S) of knitted fabrics were done after dyeing, after aging (30 months), and after exposure to UV light with a wavelength of 254 nm and 365 nm. The antibacterial effect of knitted fabrics dyed with A. millefolium L. extract on S. aureus after natural aging and treatment with UV wavelength of 254 nm results in a reduction of the zone of inhibition (Zi) from 23% (BAM) to 57% (CO), compared to Zi after dyeing. Treatment of the samples with UV light with a wavelength of 365 nm increased the Zi against S. aureus, in PES knitted fabric was even higher than after dyeing, while there were no significant changes in E. coli. In CO and BAM knitted fabrics, after aging and exposure to UV radiation, high protection factors (UPF) were found, the values of which ranged from 31.38 to 51.68. Aging and exposure to UV light affect the degree of dyeing and color fastness, which are more pronounced in knitted fabrics made of cotton and bamboo fibers compared to polyester. In addition to the research of the impact of UVA radiation (365 nm), it was important to emphasize that research on UVC radiation (254 nm) was conducted to determine how the disinfection process affects the antibacterial properties of knitted fabric treated with A. millefolium extract.The results obtained from research into the stability of antibacterial treatment to aging and UV radiation represent a significant contribution to the research in the field of medical textiles and textiles intended for the production of clothing for allergic dermatitis. These findings highlight the importance of studying the effects of UV radiation and aging processes on the color fastness and antimicrobial properties of textile materials treated with herbal extracts. The developed materials can be used to protect people from UV radiation. In addition, to create sustainable textiles, future research should include different ways of preparing extracts from plant waste, especially from juice or wine production. The obtained extracts from plant waste would be used to develop innovative processes for antimicrobial dyeing and printing of textiles. In this way, products with improved color fastness and antimicrobial properties against UV radiation and aging could be obtained. The antimicrobial effect of textiles would be tested on a larger number of microorganisms. Depending on the obtained antimicrobial effect, textiles treated with herbal extracts could be used for various purposes, for the production of children’s toys, decorative pillows, sportswear and work clothes in hospitals.