Cu2+ ion substituted nanocrystalline BaFe12O19 [Ba1 - xCuxFe12O19 (0.0 x 0.5)] hexaferrite powders were synthesized by sol-gel combustion route and its effects on structure, morphology and magnetic properties of barium hexaferrite (BaFe12O19) were presented. X-Ray Powder Diffraction (XRD), Scanning Electron Microscopy (HR-SEM), Transmission Electron Microscopy (HR-TEM) and Fourier Transform Infrared (FT-IR) analyses revealed the M-type hexagonal structure of all samples. Vibrating sample magnetometer (VSM) analyses showed that all samples have strong ferromagnetic behavior at room temperature. The crystallite size varies in a range of 23.30-35.12 nm. Both HR-SEM and HR-TEM analyses confirmed the hexagonal morphology for products. A minimum of 40.49 and a maximum of 54.36 emu/g estimated specific saturation magnetization (sigma(s)) were observed for Ba0.5Cu0.5Fe12O19 and Ba0.9Cu0.1Fe12O19 NPs, respectively. The remnant magnetization (sigma(r)) has a minimum value of 21.27 emu/g belonging to Ba0.5Cu0.5Fe12O19 and has a maximum value of 28.15 emu/g belonging to Ba0.7Cu0.3Fe12O19 NPs. The coercive fields are between 1726 Oe and 2853 Oe. K (eff) (calculated effective anisotropy constants) is changing from 2.31 x 10(5) to 3.23 x 10(5) Ergs/g. It was observed that the strong magneto-crystalline anisotropy fields, (H (a) ) above 11.0 kOe for all samples which confirmed that all samples are hard magnet. Due to their small crystallite size (smaller than 50 nm) and high saturation magnetization, Ba1 - xCuxFe12O19 (0.0 x 0.5) nanoparticles can be employed as magnetic recording materials.