A natural dye extracted from mangrove bark has been appliedto silk fabric through exhaust dyeing. For the range of conditionsused in the experiments, the optimum dyeing effect was achievedat a temperature of 90◦C, 60 min dyeing time and pH of 3. Furtherimprovement in color yield was observed with increasing dye con-centration and additional mordanting. Each metallic salt mordantgave different color shades from medium to dark reddish-brown foraluminum potassium sulfate, stannous chloride, and copper sulfateto significantly duller and darker shades for ferrous sulfate. All man-grove bark dyed silk fabric exhibited fair to very good color fastnessto crocking and fair to good light fastness with the exception of sam-ples mordanted with stannous chloride, whose light fastness wasvery poor. The water and perspiration fastness ratings were goodto very good, except for the fabric mordanted with ferrous sulfate,whose color change rating was poor to fair for perspiration fast-ness. However, the overall wash fastness was rated very poor topoor as a result of a change of color shade but there was no fadingof the color after the washing test in the basic standard detergentsolution.