The neurotoxicity of Arsenic (As) associated with Chrome Copper Arsenate (CCA)-treated wood when accompanied by chromium and copper was studied. Cells of the human neuroblastoma line SK-N-SH were cultured with CCA-treated wood leachates or with solutions containing pentavalent arsenic [As(V)], divalent copper [Cu(II)], trivalent chromium [Cr(III)] alone or in different combinations of the three elements. The toxicity was evaluated using variations in cell replication compared to controls after 96 h exposure. Exposure of SK-N-SH to CCA-treated wood leachates resulted in inhibition of cell proliferation and cell death depending on the exposure concentration, with the EC50 for cell death for As(V) in wood leachates (10.7 μM)) at lower values than for As alone (21.1 μM). As(V) toxicity was enhanced with the presence of Cu(II), while decreased with Cr(III). Dissolved Organic Matter (DOM) reduced the adsorption of As(V), but enhanced the uptake of Cr(III) into the test cells.