Since hypertensive disease and diabetes frequently occur simultaneously there exists a requirement for animal models where both pathological entities are combined. The streptozotocin (STZ)-spontaneously hypertensive rat (STZ-SHR) and the obese Zucker rat are examples of animal models where hypertension and diabetes occur simultaneously. STZ-SHRs develop a hyperglycaemic syndrome, associated with other biochemical and morphological changes that to some extent approach insulin-dependent diabetes mellitus (type 1 diabetes) combined with hypertension. The obese (Fa/?) Zucker rat is characterized by the simultaneous occurrence of obesity, hyperglycaemia, hyperinsulinaemia, hyperlipidaemia and moderate hypertension. As such it approaches the patient with non-insulin-dependent diabetes mellitus (type 2 diabetes) who is simultaneously hypertensive. Lean (fa/fa) Zucker rats are suitable controls with respect to the obese animals. Both animal models (STZ-SHRs and obese Zucker rats) were characterized with respect to their biochemical, morphometric and haemodynamic properties. Both models were examined in particular with respect to the pharmacological characteristics of their cardiovascular system, as discussed in the present survey.