An anionic surfactant, sodium octadecyl sulfate was synthesized from non-toxic n-octadecanol using chlorosulfonic acid as the sulfating agent. The synthesized surfactant was characterized by melting point, FT-IR, (1)H-NMR and ESI-Mass spectroscopic studies. Physical properties of the surfactant like Krafft point, surface tension, conductivity, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and powder X-ray diffraction (XRD) have also been studied. The surface tension and critical micelle concentration (CMC) were found to be around 48 mN/m and 0.2 mM at 30 degrees C, respectively. Both CMC and surface tension value decreased with increase in temperature. CMC decreased from 0.2 to 0.1 mM when temperature increased from 30 to 50 degrees C. The Krafft point is 56 degrees C and the melting point is 209 degrees C.