A laser-induced breakdown spectroscopy-based method has been successfully developed to quantify cesium (Cs) in solution using spectroscopically pure graphite planchets as a sample support. As Cs is a line-poor system, only five usable Cs atomic emission lines could be found and characterised by employing high-resolution system. The calibration curves of these emission lines were constructed under optimised experimental conditions. The analytical properties of these calibration curves were evaluated based on the usable dynamic range, $R^{2}$ of fitting, root mean square error cross-validation and limit of detection (LOD). The dynamic ranges of these five lines were found to be in correlation with the energy level involved in the transition. An LOD of 4 ppm was obtained using Cs(I) 852.11-nm line, which corresponds to 0.16 $\mu$g of Cs on the planchet. Based on the cross-validation approach, the best accuracy and precision ($\sim$6%) were obtained for 852.11 nm in >3000 ppm solutions, and the same is $\sim$8% for 672.33 nm and 697.33 nm in high concentrated solution of Cs.