Bone diseases and injuries have a major impact on the quality of life. Classical treatments for bone repair/regeneration/replacement have various disadvantages. Bone tissue engineering (BTE) received a great attention in the last years. Natural polymers are intensively studied in this field due to their properties (biocompatibility, biodegradability, abundance in nature, high processability). Unfortunately, their mechanical properties are poor, which is why synthetic polymers or ceramics are added in order to provide the optimal compressive, elastic or fatigue strength. Moreover, growth factors, vitamins, or antimicrobial substances are also added to enhance the cell behavior (attachment, proliferation, and differentiation). In this review, new scientific results regarding potential applications of chitosan-, alginate-, and gelatin based biocomposites in BTE will be provided, along with their in vitro and/or in vivo tests.