Carapa guianensis Aubl. (andiroba) is a tropical tree native to the Amazon and other regions of South and Central America, with significant ecological and economic importance for local communities. While its seed oil is valued for medicinal, cosmetic, and industrial uses, the fruit husks are often discarded as waste, representing a significant biomass underutilized. This study evaluates the potential of andiroba husk extract as a sustainable textile dye alternative to synthetic dyes. To obtain the natural dye, the husk powder was extracted with distilled water at 70 ℃. The resulting solution was used to dye cotton (natural and with cationization treatment), wool, linen, and silk samples. After dyeing, the samples were washed in hot and cold water and exposed to natural light for a week, with a portion of sample surfaces protected from light. Colour fastness was assessed using the CIELAB colour space, with the ΔE* parameter quantifying the difference between colours and higher ΔE* values indicate greater colour differences. Light exposure had minimal impact on colour fading, with only cotton and linen presenting a slight variation perceptible by an experienced observed (ΔE* ≅ 1.3). Dyed fabrics presented beige tones, with variations depending on the material. Cationized cotton showed the more intense colour with the highest ΔE* (22.1). The findings of this study highlight the potential of C. guianensis husk extract as a durable and stable natural dye. In addition, value can be added to a plant waste, reducing environmental impact and promoting the economic importance of this Amazonian species.