Of the various types of dye that can be used to apply polyamide fibers, acid dyes and pre-metallised acid dyes are great in use so far. However, since these acid dyeings suffer from dye loss during laundering, recourse to an aftertreatment is usually necessary to achieve adequate fastness to washing. In the case of reactive dyes, the characteristically high washfastness of dyeings comes with the concomitant advantages of brightness and low environmental impact. Despite the obvious advantages, the commercialization of reactive dyes for polyamide fibers has not gained widespread success. In this context, the rewards for approach are likely to be considerable. Heterobifunctional reactive dyes were applied to polyamide fibers using various conditions. Optimum conditions and fixation were determined. The forms in which the vinylsulphone and hydrolyzed moieties were examined using HPLC-Mass. In addition, it was found that the extent of the washfastness secured, in terms of both change in color and staining of adjacent multifiber was being acceptable.