SummaryAlkali treated pineapple leaf fibers (PALF) were used as reinforcement in an epoxy matrix. The prepared Epoxy/PALF composites were evaluated for thermal and mechanical properties. Increasing the fiber loading in Epoxy systems showed considerable enhancements in mechanical properties up to the optimum level as compared to the neat epoxy matrix. In this study, the long fibers were used in unidirectional to fabricate the composites using hand lay‐up process. Embedded composites were characterized for Fourier Transform‐Infrared spectra (FTIR), Dynamic mechanical analysis (DMA), Thermo gravimetric analysis (TGA), Scanning electron microscopy (SEM) and Mechanical properties like tensile, flexural and impact strength. The mechanical properties of the treated composites were observed to be good when compared to untreated composites and treated composites gave increased mechanical properties and there is no considerable changes in the thermal properties. A comparative study in the epoxy matrix using treated and untreated fibers is elaborated. The enhanced properties of the treated PALF/epoxy composites, increases the scope of the application in automobile parts.