<p>A series of bio-functionalized guar gum (GG)-based waterborne polyurethane dispersions (GWPUDs) for textile applications was synthesized by step-growth polymerization reaction. The initial stage included synthesizing a hydrophilic-NCO-ended polyurethane pre-polymer utilizing GG as the polyol, isophorone diisocyanate (IPDI), and dimethylolpropionic acid (DMPA). In the second stage, five samples were obtained by adding varying moles of 1,4 butanediol (BDO) as a chain extender to&#xa0;hydrophilic-NCO-ended polyurethane pre-polymer. In the next step, neutralization was carried out by using triethylamine, and finally, distilled water was added to obtain GWPUDs. Fourier transform infrared spectroscopy was used to identify the presence of GG and BDO in the synthesized GWPUDs matrix (disappearance of − NCO peak at 2158.1 cm⁻¹ and appearance of –NH stretching vibration peak at 3324.8 cm⁻¹), and dynamic light scattering was used to measure the particle size. The X-ray diffraction method was used to investigate the crystallinity, and the findings indicated that GWPUDs are semi-crystalline with a greater value of % crystallinity (42.21%) for GWPUD-3. The thermogravimetric study showed that as the proportion of GG increased, the thermal stability of GWPUDs improved. By using GWPUDs on printed and dyed fabrics by the pad dry cure method, textile performances, including colorfastness to washing, colorfastness to perspiration, pilling, and tensile strength, were evaluated. The findings demonstrate the improvement in textile evaluations, including colorfastness to washing (3–4 to 4–5), colorfastness to perspiration (3–4 to 4–5), and pilling (4 to 4–5). The treated fabric's tensile strength increased. Gram-positive <i>Staphylococcus aureus</i> ATCC 25923 and gram-negative <i>Escherichia coli</i> ATCC 25922 were inhibited by the antibacterial activity of dyed and printed cloth treated with GWPUDs, demonstrating their ability to inhibit bacteria.</p>