Two experiments examined whether superior observational conditioning of fear occurs in observer rhesus monkeys that watch model monkeys exhibit an intense fear of fear-relevant, as compared with fear-irrelevant, stimuli. In both experiments, videotapes of model monkeys behaving fearfully were spliced so that it appeared that the models were reacting fearfully either to fear-relevant stimuli (toy snakes or a toy crocodile), or to fear-irrelevant stimuli (flowers or a toy rabbit). Observer groups watched one of four kinds of videotapes for 12 sessions. Results indicated that observers acquired a fear of fear-relevant stimuli (toy snakes and toy crocodile), but not of fear-irrelevant stimuli (flowers and toy rabbit). Implications of the present results for the preparedness theory of phobias are discussed.