The use of lignocellulosic fibers into polymer matrices gained attention of the researchers and brought substantial research. The main objective of this research work is to determine the thermal characteristics and hygrothermal aging of untreated and surface modified Agave Cantala plant fiber-reinforced polylactide composites. Cellulosic fibers were extracted from the fleshy leaves of the plant by water and mechanical retting processes. The extracted fibers were treated with trimethoxy methyl silane and fabrication of the composites was done using matched die molding method. These composites are characterized by thermo-gravimetry analysis, Fourier transform infrared spectroscopy, X-ray diffraction study, hygrothermal aging, energy dispersive X-ray spectroscopy and field emission scanning electron microscopy analysis. The results showed the trimethoxy methyl silane treated A. Cantala treated fiber reinforced composites exhibiting better thermal, hygrothermal, and morphological behavior.