The food processing industry generates huge amount of chicken eggshell waste per year worldwide. This solid waste is composed mainly of calcite (CaCO₃), and is considered to be a waste material of difficult final disposal. In recent years calcium phosphate-based biomaterials have attracted high interest in medical and dental applications for bone grafting and implants. This work focused on the synthesis and characterization of calcium phosphate-based biomaterials via wet chemical precipitation method in different HNO₃ concentrations (1 M to 3 M). The chicken eggshell waste was used as an alternative calcium precursor. The resulting powders were calcined at 900 ºC for 2 h, and then characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM/EDS), thermogravimetric analysis (TG), differential thermal analysis (DTA), and Fourier transform infrared spectroscopy (FTIR). The XRD, SEM/EDS, TG, DTA, and FTIR measurement results obtained agree very well. The experimental results showed that it is possible to obtain different calcium phosphate-based nanopowders such as pure β-calcium pyrophosphate (β-CPP) and biphasic calcium phosphate (β-CPP/β-TCP mixture), β-TCP (β-tricalcium phosphate), depending on the HNO₃ concentration. The calcium phosphate nanopowders presented average crystallite size in the range from 49.74 nm to 61.47 nm. Such calcium phosphate-based nanopowders produced are highly promising candidates for biomedical field applications.