We investigate the feasibility of laser-induced breakdown spectroscopy for determination of heavy metal Pb in a $\mathrm{Pb}({\mathrm{NO}}_3{)}_2$ aqueous solution by using a simple homemade vertical jet device and nanosecond laser pulses. Key experimental parameters that affect the analytical performance, such as delay of the time of observation, laser pulse energy, and liquid flow rate are optimized for the best limit of detection (LOD). The LOD was determined using Pb I emission at $405.781\mathrm{nm}$ , and after optimization, the $3\sigma$ LOD was found to be at the level of $60\mathrm{ppm}$ .