Analysis of essential and toxic elements is vital analytical process that could employ different analytical instruments depending on the analytical procedures. This paper presents the results of comparison of ICP-MS and FAAS as methods of quantification of the essential elements in the medicinal plants.  The essential elements in nineteen commonly used medicinal plants in Nyamira County, Kenya were quantified using the ICP-MS and FAAS techniques.  It was revealed that the results obtained by the two methods were statistically not different. The correlation coefficient values for the results of the two techniques in two study areas were close to unit indicating very strong positive relationship between the elemental levels determined by the two methods, though ICP-MS gave slightly higher values. However, any of the two methods could be used for the analytical quantification of the mineral elements in plants and since FAAS is cheap to purchase, maintain and provides reliable results it can be used in the analysis of various elements in plant, environmental and soil samples.