AbstractThe development of microcrystalline cellulose from banana flower pistil and its twill weaved woven abaca polyester composites were studied in this research. The aim of this research was to explore the viscoelastic, fatigue, and mechanical behavior of surface‐treated twill weaved abaca fiber and unsaturated polyester incorporating banana flower pistil cellulose particles for various composite combinations. Hand layup process was used to construct the bio‐composite laminates, which were then tested in accordance with american society for testing and materials (ASTM) standards. The maximum tensile strength and modulus, flexural strength and modulus, Izod impact strength, as well asinter laminar shear strength (ILSS) values by addition of 3.0 vol% of cellulose were about 124 MPa, 4.48 GPa, 163 MPa, 5.36 GPa, 5.33 J/m2, and 27 MPa respectively, whereas composite having 5.0 vol% of cellulose gave better hardness of 82 shore‐D. Incorporation of cellulose by 3.0 vol% with 50 vol% of abaca fiber increases fatigue life counts up to 35,480, 29,039, 24,802, and 18,247 for 25%, 50%, 70%, and 90% of ultimate tensile strength (UTS) respectively. On comparing all other composite combinations, the composite containing 3.0 vol% of cellulose shows the highest storage modulus of up to 5.6 GPa and the lowest loss factor of 0.38. The scanning electron microscopy (SEM) fractography shows the improved adhesion between fiber and matrix due to the silane treatment on cellulose and abaca fiber. These novel functional materials could be employed in a large range of applications, including industrial, automobile, electronic and household equipment.