Silk fabrics were chemically modified with different kinds of dibasic acid anhydrides. Samples with different acyl contents, ranging from 24 to 107 mol/10(5) g, were obtained by reaction with succinic (S), glutaric (G), phthalic (PA), and o-sulfobenzoic (OSBA) anhydrides. Dyeability with a cationic dye (Rhodamine B, C.I. Basic Violet 10) was determined by measuring dye uptake and K/S values. Following acylation, the absorption of basic dye was significantly enhanced for all samples. The maximum dye uptake was attained by OSBA-treated silk fabrics, while samples treated with S, G, and PA did not differ significantly. Dye uptake increased regardless of the acyl content, at least in the range examined. Reflectance measurements and K/S values confirmed the trend evidenced by dye uptake results.