A simultaneous cleanup method for the determination of pesticide residues in agricultural products by GC and HPLC was developed. The elution patterns of 120 pesticides from a hard gel-type GPC column and an ENVI(TM)-Carb/LC-NH2 mini-column were examined. Most of the pesticides were eluted in the 55 similar to 160 mt fraction from GPC with 30% acetone-cyclohexane (v/v) and in the 0 similar to 20 mt fraction from the mini-column with 25% toluene-acetonitrile (v/v). The results showed that these two cleanup methods were applicable for most of the pesticides. A sample was extracted with acetone and filtered. The extract was partitioned with saturated ammonium sulfate-ethyl acetate. The extract was dehydrated, evaporated in vacuo, dissolved in the GPC mobile phase and cleaned up by GPC. The eluate fraction of pesticides was evaporated in vacuo and dissolved in acetone. An aliquot of the acetone solution was cleaned up on a mini-column. The eluate was evaporated in vacuo and dissolved in acetone or acetonitrile. The sample was determined with GC or HPLC. The additional mini-column cleanup was especially effective for HPLC analysis. Approximately 110 out of 120 pesticides spiked into 6 kinds of agricultural products gave good recoveries with combined cleanup using GPC and the mini-column, which is considered to be satisfactory for pesticide residue monitoring by GC and HPLC.