Inflammatory and infectious diseases include many different clinical conditions not often well recognised and characterized with conventional radiology and biochemical tests. Radiological techniques (TC, MRI, US) show anatomical changes that usually occur in chronic stages of the disease leading to a delayed diagnosis and therapy. The possibility of Nuclear Medicine imaging to detect biological and biochemical changes in the earliest phases of diseases, allow the clinician not only to promptly identify the infective or inflammatory focus, but also to establish the best therapeutic approach for the patient. The recent availability of different monoclonal antibodies and analogues of growth and signalling factors offers physicians a wide spectrum of promising radiopharmaceuticals as markers for different pathological events. Therefore, NM may help in therapy decision making, management and follow-up through the evaluation of the expression of these specific molecules, leading to the development of personalized therapies. The appeal to Nuclear Medicine imaging is becoming, indeed, more and more widespread not only for diagnostic purposes, but also for monitoring drug efficacy. Several advances have been observed in this field, and they seem to be very promising for a tailored medicine.