The present study was aimed at estimating the leaching behavior of waste natural stone slurries used in earth and road construction. For this purpose, concentration levels of Ca 2+ and Mg 2+ ions, which were extracted from the soil and the waste natural stone slurries mixed into soils in road and earthworks by synthetic precipitation leaching procedure (SPLP) were detected. The results obtained from Ca 2+ and Mg 2+ analysis implied that each type of the waste materials had a Ca 2+ and Mg 2+ concentration lower than the initial concentration for the waste material ratios of 0, 10, 20, 30 and 40% examined after any leaching procedure. In the present study, final pH value of any leaching medium (initially adjusted to three different pH values; 4.2, 5.0 and 6.0) was also considered as an important environmental parameter. The maximum final pH value was found to be 9.8 and it was also found that this value slightly exceeds the permitted value of Turkish regulations. ©2011 Academic Journals.