Abstract: Differences in behavioural characteristics between individuals of the same species are often described as being due to the temperament of the individuals. These differences can have enormous implications for welfare with some individuals apparently being able to adapt to environmental challenge more easily than others. Such differences have resulted in animals often being described as either `active' copers, which try to escape from or remove an aversive stimulus, or `passive' copers, which show no outward signs of a situation being aversive, thus, appearing to be unaffected. Tests previously developed to assess the temperament of animals have been criticised for several reasons. Behaviour is often recorded and categorised using methods that are not objective and tests are generally carried out once with no consideration of whether or not behavioural responses are consistent over time. This study takes these factors into account. The behaviour of 33 horses was recorded in three types of test--an arena test, response to a person and response to an object. In order to test whether or not responses were consistent over time, the tests were repeated three times with an average of 9 days between trials. Test results were validated using responses from questionnaires completed by the farm team leader. The data were analysed using an initial principal component analysis (PCA) and factor analysis. The horses were found to behave consistently over the three trials in their responses in the arena test. The responses to the person test and the object test were similar to each other; however, these responses were not consistent over trials. The behaviour in the arena test was unable to be used to make a prediction of behaviour in the person and object tests and vice versa. The responses shown by the horses did not enable them to be categorised as either active or passive copers. Behavioural responses in the tests were not predictive of the response to a startle test (water spray), nor could they be used to predict status or response to being reintroduced to the group after testing. There was no relationship between the responses in the tests and the ratings given by the farm team leader. It was concluded that horses vary widely in their responses to artificial behavioural tests, with only the responses to an open-field arena test being consistent over time, and therefore, the only type of test which can indicate some core factor of temperament.