Cu 2+ ion substituted nanocrystalline BaFe 12 O 19 Ba 1 − x Cu x Fe 12 O 19 (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 (BaFe 12 O 19 ) 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 (σ s ) were observed for Ba 0.5 Cu 0.5 Fe 12 O 19 and Ba 0.9 Cu 0.1 Fe 12 O 19 NPs, respectively. The remnant magnetization (σ r ) has a minimum value of 21.27 emu/g belonging to Ba 0.5 Cu 0.5 Fe 12 O 19 and has a maximum value of 28.15 emu/g belonging to Ba 0.7 Cu 0.3 Fe 12 O 19 NPs. The coercive fields are between 1726 Oe and 2853 Oe. K eff (calculated effective anisotropy constants) is changing from 2.31 × 10 5 to 3.23 × 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, Ba 1 − x Cu x Fe 12 O 19 (0.0 ≤ x ≤ 0.5) nanoparticles can be employed as magnetic recording materials.