A robust synthesis for magnetic CoFe2O4 nanoparticles via a hydrothermal technique was investigated. The prepared magnetic nanoparticles were characterized using powder X‐ray diffraction, scanning, transmission and high‐resolution transmission electron microscopies, energy‐dispersive X‐ray and infrared spectroscopies, thermogravimetric analysis and vibrating sample magnetometry. Based on the obtained data, the prepared powder was composed of ultrafine particles in nanometer size range with highly homogeneous spherical shape and elemental composition. Moreover, the prepared magnetic CoFe2O4 nanoparticles were used as an efficient catalyst for green synthesis of tetrahydropyridines and pyrrole derivatives in excellent yields, with easy work‐up and purification of products by non‐chromatographic methods. The catalyst can be recovered for subsequent reactions and reused without any appreciable loss of activity.