Development of pineapple leaf fiber (PALF)-based polymer composites has gain interests due to sustainable and environmental benefits when compared with synthetic-based non-degradable fibers. However, the hydrophilic PALF has poor interfacial bonding with the thermosetting and thermoplastic polymers which are hydrophobic. Moreover, this hydrophilic nature of PLAF leads to more moisture absorption rate, which results in degradation of overall properties. This issue can be addressed by modifying the surface of the fibers. Therefore, a comprehensive understanding of the effect of fiber surface modification on various properties and adhesion with polymers is a key for improving the performance of the PALF and its composites. In this context, the performance of surface modified PALF and its applications are elaborately discussed in this chapter.