It has been known that some industrial liquid wastes usually contain a variety of heavy metals such as Cd (Cadmium), Pb (Lead), Ni (Nickel), Cr (Chromium), As (Arsenic), Cu (Copper), and Fe (Iron). If these liquid wastes are not managed properly, it will damage the water environment, especially the water body like rivers and lakes. Various methods have been applied to remove heavy metals from these liquid wastes, such as precipitation, ion exchange, membrane processes, adsorption, coagulation, and flotation. One common method that can be applied to manage waste that contain heavy metals is an adsorption method. Recently, it has been a trend to use biomass based adsorbent or usually called by bio-adsorbent. In this research bio-adsorbent has been prepared from cassava stem pith powder. This research was conducted to study the capability of bio-adsorbent made of cassava stem pith powder to adsorb Pb2 + metal ions. Several variables have been used during the adsorption test, which are pH condition (3, 4, 5), adsorption time (10, 20, 50, 120 mins), and initial concentrations (5, 10, 20 mg/L). The adsorption process involving functional groups contained in the adsorbent so that there will be interactions between the adsorbents with Pb2+ metal ions. The sample characterization was carried out using an Atomic Absorption Spectroscopy (AAS) apparatus. The adsorption test results showed that the optimum conditions for Pb2+ adsorption by the bio-adsorbent occured at pH = 3, adsorption time of 120 minutes, and initial concentration of 5 mg/L, in which the capacity was about 2.525 mg/g with the percent removal (R%) of 88.88%.