In this study, studies on composite materials formed by organic reinforcement materials with polylactic acid (PLA) were examined. Organic reinforcing materials are widely used in polymer matrix composites because their natural fibres are strong, lightweight, low weight, high specific strength, inexpensive, environmentally friendly and biodegradable in nature. Biodegradable polymers are of great importance in various fields of technological development. Studies on this subject are becoming widespread day by day. PLA, one of the biodegradable polymers, is used very effectively in the medical field, packaging and packaging, environmental applications, textile applications. In general, organic reinforced composites; fibres, wood, sisal, hemp, hemp, flax, kenaf, bamboo, apricot kernel shell, etc. are obtained from plant-derived natural materials. In this study, the mechanical properties of composite materials produced by reinforcing organic materials into PLA polymer matrix, production techniques, effects of reinforcing elements on PLA matrix, added reinforcement ratios, effects of interfacial materials are examined and the findings and results obtained are compiled.