As early as the 1950s there were warnings about the toxicity of the synthetic oestrogen diethylstilbestrol (DES), but in the Netherlands this drug continued to be prescribed to pregnant women up to the late 1970s. Until recently the periodic check-ups of children born from these pregnancies - the so-called DES Daughters - was mainly focused on genital abnormalities and the sporadically occurring clear cell adenocarcinoma of the vagina. As they grow older, the risk of this and similar types of carcinoma decreases and the nature of the periodic check-ups changes. However, check-ups cannot be omitted as the 5-yearly population study for cervical cancer is not suitable for detecting clear cell adenocarcinoma. DES Daughters should continue to receive a 2-yearly cytological check-up from their general practitioner until at least the age of 60. Now more than ever, physicians must be particularly vigilant in checking for the non-oncological late effects of DES.