This paper reports an experimental study wherein the quantity and distribution of oily contaminants present in flame-resistant fabrics (FR) after contamination and decontamination was determined using radiotracer analysis and scanning electron microscopy. The experimental variables were fabric type, laundry treatment, and number of contamination/decontamination cycles. Laundry treatments involving a pre-wash product were the most effective in removing oil from all FR fabrics regardless of the number of contamination/ decontamination cycles. Accumulation of oily contaminants was noted after five contamination/ decontamination cycles regardless of the fabric type or laundry treatment. FR cotton/nylon retained the most residual oil for all laundry treatments. No oil remained in the interior of the aramid, viscose, and nylon fibers, but rather remained on the surface so that it was removed easily during decontamination. A significant quantity of oil was located in the interior of the cotton fibers, making it difficult to remove during decontamination.