<p>This study investigates the structural, optical, and magnetic properties of Perovskite lanthanum aluminate (LaAlO₃) nanoparticles synthesized by the Pechini method. Lanthanum aluminate, a material known for its exceptional optical and magnetic properties, was synthesized under control conditions to achieve nanoparticles with well-defined characteristics. X-ray diffraction (XRD) and Rietveld refinement were employed to determine the crystal structure and phase purity. The crystallite size and lattice microstrain were estimated to use the Size-Strain plot. The crystallite size value was 38.1138 nm and the lattice microstrain was 0.0509. At the same time, Fourier-transform infrared spectroscopy (FTIR) was used to investigate functional groups and bonding. The optical properties, including the bandgap and light absorption behavior, were analyzed using UV–Vis spectroscopy. The calculated value of the energy gap was 4.28 eV using the Tauc method. The magnetic properties were examined using a Vibrating Sample Magnetometer (VSM). The (M–H) curve shows a diamagnetic behavior for LaAlO₃ Nanoparticle (NPs). The results demonstrate the influence of synthesis parameters on the material phase composition, optical absorption, and magnetic behavior, suggesting potential applications in catalysis, spintronics, and optoelectronics. This comprehensive study highlights the versatility of the Pechini method in tailoring the properties of lanthanum aluminate for advanced technological applications.</p>