An experiment was conducted during 1986-87 to study the persistence of dodine (65% N-dodecylaguanidine acetate) on apple (Malus domestica Borkh.) fruits at fruit-finish stage under orchard conditions by calorimetric method. The average residues 15 days after application were 0.62, 1.07 and 1.32 mg/kg corresponding respectively to the loss of 82.77, 72.20 and 73.06% @ 1.5, 3.0 and 4.5 kg/ha. The residue half life (RL50) and waiting period (maximum residue limit 2.0 mg/kg) were 8.5 and 8.0 days respectively. However, the persistence of dodine residues on apple fruits would be up to 23 days at recommended (3.00 kg/ha) dosage for apple-scab [Venturia inaequalis (Cooke) Winter] management.