Residues of the contact fungicide Cymoxanil in grapes were determined by a multidimensional multicolumn high pressure liquid chromatography technique (MC-HPLC). The sample pretreatment is a simple water extraction. Further clean-up and trace enrichment of an aliquot of the aqueous acidic sample solution is performed on-line via an automatized microprocessor controlled MC-HPLC system. In the range of 0.05-2.0 mg/kg grapes good linearity is achieved. Recoveries of Cymoxanil added to untreated grapes range between 70% and 80% at 0.05 and 2.0 mg/kg values, respectively, with a reproductibility of s +/- 3% at 0.2 mg/kg (n = 5). The total time for analysis is approximately 30 min.