A series of oligomeric acid azo dyes has been prepared by coupling various aromatic diazonium salts to 1-naphthol-furfuraldehyde (1-NF) and 2-naphthol-furfuraldehyde (2-NF) oligomers. They were evaluated in terms of their softning points, yield, colour, solubility and UV-Vis spectra. Structure-property relationships are discussed and dyeings on wool, silk and nylon-6,6 assessed. Dyeings on wool, silk and nylon-6,6 resulted in yellow, orange and brown to red colourations having excellent fastness to light and washing.