ABSTRACT. The degradation of the postharvest fungicides imazalil, orthophenylphenol, and pyrimethanil was studied on Clementine mandarins during packinghouse storage for a 28 day period at 4 C. Fruits to which orthophenylphenol was applied, were treated with imazalil and pyrimethanil at doses of 1000 and 2000 mg L1, using cascade application for the later and cascade and wax for the former. The decay of the three fungicides was evaluated using an in-house validated analytical procedure that includes the extraction and dispersive clean up of the samples followed by the GC?MS determination of the pesticide residues. The impact of fruit storage time on pesticide residues concentration was assessed. The residues found for the different application technologies were always below the established Maximum Residue Limits by the Codex Alimentarius and the European Union (5 mg kg1 for imazalil, 7 and 8 mg kg1 for pyrimethanil, and 10 mg kg1 and 5 mg kg1 for orthophenylphenol). The fungicides dissipated differentially. Pyrimethanil showed little degradation, if any, at both tested concentrations, but the half-life of imazalil on the fruit was 15?18 days, independent of the application technology. Orthophenylphenol dissipated with a half-life of 15 days. The initial imazalil residue found after cascade treatment was not significantly different between the doses studied (p