The effect of various phenols and aromatic amines on the dynamics of the peroxidase-catalyzed aerobic oxidation of NADH was investigated. We demonstrate that several aromatic compounds may substitute for 2,4-dichlorophenol in inducing sustained oscillations and complex dynamics in the reaction. These aromatic compounds can also act as substrates in the classical peroxidase reaction. Since some of the aromatic compounds studied are naturally occurring substrates for peroxidases, we conjecture that oscillations and complex dynamics may well occur in the intact plant.