Comparison study for the determination of metal contents in three herbal medicinal plants was achieved by using atomic absorption spectrometry at two times (2012 and 2015). Also, this study was done by applying two sample preparation methods that were wet and dry. The obtained results showed that the effect of uncontrolled storage conditions had no influence on cadmium content in all time storage- sample preparation conditions. Iron content showed increasing in term of concentration while lead was with partial increase using dry preparation method and partial decrease using wet preparation method. The other measured elements, calcium, magnesium, and chromium contents were with strong effect. All measured elements with serious health problems were compared with highest acceptable values by World Health Organization (WHO).