The development of nuclear medicine has resulted in several effective routine methods in diagnosis and therapy. There is an ongoing discussion about the future of activity based on the fast development of ultrasound, CT and MR. In such discussions, it is often forgotten that nuclear medicine is also a dynamic diagnostic tool under continuous progress. As seen from this historical review, nuclear medicine has grown from quite simple in vitro tests to very advanced methods to image organ function. This is the result of the development of radiopharmaceuticals and instrumentation. Today, development is moving towards what is called receptor scintigraphy, i.e., the use of radiopharmaceuticals which are very specific to certain diseases, for instance, tumours. Even at present there is no other method for early detection of bone metastases than bone scintigraphy. Also, there is no other method to determine the regional myocardial blood flow both at stress and at rest, than myocardial scintigraphy. Nuclear medicine will remain an important diagnostic tool as long as it employs people with engagement and interest. Such people will also guarantee that the hospital management will supply the activity with funds for the necessary investments.