Several mixtures of the organophosphorus extractants dibutyl butyl phosphonate (DBBP) and bis(2-ethylhexyl)phosphoric acid (D2EHPA) have been investigated for arsenic removal from sulfuric acid media in a synthetic copper electrolyte solution. The extraction system has been characterized in terms of As(V), metal [Fe(III), Sb(V), Ni(II), Cu(II)], and H2SO4 loadings; extraction and stripping contact times; organic-phase composition; organic-to-aqueous ratio; and selectivity. McCabe-Thiele interpolations indicate a reduction in the arsenic electrolyte concentration from 7300 to 2000 mg/L in two theoretical stages at O/A = 4 for the 1.5 M DBBP-0.5 M D2EHPA mixture at 50 degreesC. For mixtures of DBBP and D2EHPA, there is an increase in the arsenic distribution (synergism) compared to DBBP alone, and at the same time, extractant loss and sulfuric acid coextraction are diminished.