Continuous direct measurement of feline arterial blood pressure (ABP) was carried out via a modified method with percutaneous, ultrasound guided catheterization of the common carotid artery. In 21 healthy, conscious cats the ABP was measured during rest, alertness and activity. Furthermore, the ABP response to being petted by familiar and unfamiliar persons was assessed. Linear mixed modelling revealed that the mean blood pressure (MBP) in resting cats (114.6mmHg) was lower (P<0.001) than in alert cats (122.7mmHg), which was lower (P<0.001) than that of active cats (136.8mmHg). The MBP during petting by a familiar person (144.7mmHg) tended to be higher (P=0.065) than that during petting by an unfamiliar person (139.4mmHg). The MBP of active cats was lower (P=0.003) than MBP of cats petted by a familiar person, but not different from MBP of cats petted by an unfamiliar person. The MBP returned to resting values between 16 and 20min after the familiar person had left, whereas resting values were reached between 11 and 15min after the unfamiliar person had left. The complications of the described method were limited considering the potential risks of continuous direct ABP measurement. In conclusion, the described technique enables accurate measurement of feline ABP, which is influenced by the cat's activity level and the familiarity of persons.