A laboratory experiment, was carried out on synthetic goethite and zerovalent iron (ZVI) to study the competition between AsO₄^3-(10µg As mL^-1)and PO₄^3-, SeO₄^2-, SO₄^2- and MoO₄^2- at different ratios (1:0, 1:1, 1:2 and 2:1) on the adsorption surfaces of the selected minerals. Obtained data showed that, at pH 7.0 a quantity  of 2891 µg As g^-1 goethite  was adsorbed from the added As(V) (AsO₄^3-), with increasing the pH above 9.0 the adsorbed AsO₄^3- was decreased to be 1662 and 945 µg As g^-1 goethite at pH 11.0 and 11.8 , respectively. On the other hand, the amount of adsorbed As(V) on ZVI recorded 23590 µg As g^-1 at pH 4.0 and decreased to be 15620 and 983 µg As g^-1 ZVI at pH 9.5 and 12.0, respectively. Adsorption of As(V) on both goethite and ZVI was decreased with increasing pH when As(V) was added alone or with PO₄^3- at As :P ratios of 1:0, 1:1 and 1:2. However, more pronounced increases in AsO₄^3- adsorption was noticed when AsO₄^3- was added at 2:1 ratio as compared to PO₄^3- with all tested pH values. The adsorption affinity of goethite and ZVI to AsO₄^3-was affected largely by pH and arsenate concentration in the equilibrium solution. It could be mentioned that PO₄^3- could not compete well with arsenate on the specific sites of AsO₄^3- if its ratio to AsO₄^3- was less than 2:1. These results indicate that the preference of adsorption  sites to AsO₄^3- was mainly affected by pH values and the  concentration of associated oxyanions. With respect to the competition between AsO₄^3-and SeO₄^2-,MoO₄^2- and SO₄^2-, obtained data also  indicated that the adsorbed AsO₄^3-on  both goethite and ZVI  was decreased  more at As:Se ratio of 1:2 as compared with other ratios.Selenate (SeO₄^2-) had competed with AsO₄^3-on the adsorption sites of both goethite and ZVI, and reduced the amount of adsorbed AsO₄^3- .Increasing the initial concentration of adsorbed  As comparing with  selenate or any other oxyanions alleviated the effect of competing  oxyanions as indicated with As:Se ratio of 2:1. More than 95% of As(V)was adsorbed on both goethite and ZVI below pH 4.0 in single AsO₄^3-anion and binary with MoO₄^2-anion systems. These data suggested that MoO₄^2- occupies a fraction of the pH- dependent As(V) adsorption sites on the studied minerals and there was another distinct fraction  of sites had higher affinity for As MoO₄^2- at low pH. Obtained  data also indicated that, the preference of the adsorbents to AsO₄^3-over SO­­­₄^2- was declared when  they added together.