In our visual analysis of behaviour, we may go beyond a perceptual description of actions and make inferences about mental states (intentions and beliefs). For example, we can see the action of reaching to an object as goal-directed or the action of looking as attention to a specific target. More complexly, we can infer from reaching an intention or desire to get an object (even if the action is unsuccessful), and from attention to an event the acquisition of knowledge about that event, or conversely from lack of attention we can infer ignorance or even false beliefs. The extent to which non-human primates are able to make such inferences is unclear. We consider here, (i) the visual processing that is available to macaque monkeys to describe behaviour of others, and (ii) experiments on the behavioural capacity of monkeys to exploit such visual processing to predict events based on another's knowledge states. We conclude that monkeys possess the neural machinery for discriminating intentional behaviour and predicting the events (end postures or reappearance) from actions. At the behavioural level we found evidence that monkey eye movements anticipate events based on an awareness of action of others, however, we were unable to demonstrate the capacity to represent another's knowledge states.