The feasibility of simultaneous speciation of arsenic and selenium compounds after ion chromatographic separation was investigated using inductively coupled plasma mass spectrometry (ICP-MS) as multielement specific detector. Separation conditions were optimized. Under the optimized conditions, six arsenic species: arsenous acid [As (III)], methylarsonic acid (MA), dimethylarsinic acid (DMA), arsenic acid [As(V)], arsenobetaine (AsB), arsenocholine (AsC), and four selenium species: selenous acid [Se(IV)], trimethylselenonium cation (TMSe+), selenocystine (SeCys), selenomethionine (SeMet), can be separated in the same injection within 8 minutes and determined at environmental concentration levels. The detection limits are estimated in the range of 0.04–0.6 μg/L for arsenic compounds and 0.18–0.35 μg/L for selenium compounds.