A straightforward and efficient method was developed for the determination of intact daminozide in apples and apple leaves. After extraction with methanol and a clean-up step using a graphitized carbon cartridge, the extract was analysed by ion-trap liquid chromatography-tandem mass spectrometry (LC-MS-MS) using atmospheric pressure chemical ionisation in the positive ion mode. Recoveries for apple were 98-102% with a R.S.D.≤11% (n=6) and for leaves were 112-116% with a R.S.D.≤18% (n=6). The limits of detection were 0.008 and 0.02 mg/kg for apples and leaves, respectively. Copyright (C) 1999 Elsevier Science B.V.