Tin oxide nanoparticles were synthesized via hydrothermal method using a non-ionic surfactant, oleyl amine (OLM), in the presence of urea. The reactions were carried out at different calcination temperatures and varying concentrations of surfactant and urea. The effect of these reaction parameters on the particles' size, distribution, surface area, and the average pore diameter were investigated using X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis, thermogravimetric analysis, Brunauer-Emmett-Teller method, and Fourier transform infrared spectroscopy. Larger tin oxide nanoparticles were obtained with higher concentrations of urea. At the optimum experimental conditions, tin oxide nanoparticles with mean particle size of 9.92 nm and surface area of 31.82 m(2) g(-1) were obtained. Particle size further decreased to 5.36 nm with the addition of surfactant having a concentration below CMC. Elimination of surfactant from tin-surfactant composites after calcination yielded mesoporous particles but the increase in calcination temperature resulted in larger and highly aggregated tin oxide particles.