Overdiagnosis of prostatic cancer easily leads to overtreatment, whereby the patients are also exposed to the adverse effects of the treatments. Active surveillance has been raised as an alternative to the treatments of prostatic cancer with a good prognosis. Active surveillance means that instead of immediate curative treatment, a patient suited for radical treatments by his age and condition is under careful monitoring. Active surveillance aims to pick out from the wide group of prostatic cancer patients those, who present sings of progressive disease, and to provide the curative treatment later, whereby harm-free lifetime will be extended.