Given the ash level of medical waste incineration utilized as a raw material mixture that contains metal compounds, dumping the paving block immersion water into rivers could result in a drop in water quality. The purpose of this study is to evaluate water quality during immersion of paving blocks made from medical waste incineration ash. Water quality was measured by five measurements in water before immersion, soaking for 7 days, 14 days, 21 days, and 28 days. The test method used is in accordance with SNI 6989-84:2019. The metal compounds examined in this study were Pb (lead), Copper (Cu), Nickel (Ni), and cadmium (Cd). Laboratory tests were conducted at the Jasa Tirta I Environmental Laboratory and the Sukoharjo Environmental Service. It can be concluded that there is no pollution due to heavy metals contained in paving blocks. The results show that the soaking water for 7 to 28 days is still below the specified quality, so paving block-making activities using a mixture of medical waste incineration ashes can be carried out. The need for other studies measuring the levels of other metals such as Cr, Hg, Sn, Ti, and Zn.