In this study, water-repellent, oil-repellent and flame-retardant cotton fabrics were developed by solgel technique. With this aim, nanosols were prepared using tetraethylorthosilicate and hexadecyltrimethoxysilane as precursors, guanidine dihydrogen phosphate as flame-retardant agent and Guard AFB as conventional water-oil-repellent agent, solvents and chelating agents. Then, to AC105, VA7110, PU1110 and FC9005 as polymeric additives, with/without FX8000 or urea and formaldehyde as cross-linking agents, were added some nanosols to improve washing fastness of the fabric samples. Cotton fabrics were treated with nanosols without polymeric additives by pad-dry-cure process, while they were coated with nanosols containing polymeric additives by knife-over-roll coating. Water-oil-repellent properties, flame-retardant properties, washing fastness, contact angle, whiteness, tear strength and add-on values of the coated fabric samples were determined. It was found that the cotton fabrics with good water-oil-repellence and flame-retardant properties with relatively durable properties could be produced using nanosols containing guanidine dihydrogen phosphate and urea, together with tetraethylorthosilicate and hexadecyltrimethoxysilane as precursors, and lower concentrations of Guard AFB as commercial water-oil-repellent agent. However, the fabric samples were still not sufficiently durable when washed. It was deduced that the durability of cotton fabric during washing is developed by means of treatment with nanosols containing polyvinyl acetate-based polymer.