The interest for natural fibers as an alternative to synthetic fibers is no doubt on the raise. This interest is anchored on the fact that natural fibers are eco-friendly, renewable, affordable, have low density and can be processed with the existing processing methods. However, before these natural fibers can be used, they must be treated in order to modify their surface properties. The methods for surface modification of natural fibers include: biological, chemical and physical. These methods impact different effect on the treated fibers. Some of these effects are desirous while some are not, depending on the intended application. This chapter intends to review the different types of modification methods in use today and examine in detail, their effects on the properties and performance of the treated fiber.