In this study, hematite (α-Fe2O3) nanoparticles were synthesized using the sol-gel method. The physical properties are modified by the citric acid concentration used as a fuel. The XRD results showed that the obtained sample had a rhombohedral (hexagonal) structure with space group R3c. The crystallite size calculated using the Scherer formula at the strongest peak was found to be 32.14, 24.58, and 23.21 nm with an increase in citric acid molarity of 0.3, 0.4, and 0.5, respectively. The absorption band in the FTIR spectrum shows the characteristics of hematite nanoparticles. Finally, the confirmed magnetic properties of the VSM data revealed a significant decrease in the coercive field, that is, 935, 610, and 548 Oe, as the citric acid concentration increased by 0.3, 0.4, and 0.4, respectively.