Endocrine disruption has been a topic of public concern for many years and its study remains high on the scientific agenda. Endocrine disrupters (EDs) are compounds which may be of industrial or natural origin and which act to dysregulate steroid function and metabolism. As well as their actions on nuclear steroid receptors, EDs can inhibit the pathways of steroid synthesis and degradation. They not only affect reproductive function but also affect a range of tissues which are steroid sensitive such as the central nervous system and thyroid. Results from the latest studies suggest that EDs may also affect the immune system, glucose homeostasis and can act as epigenetic modulators resulting in transgenerational effects. Research in this area has led to the development of drugs used in the treatment of several types of hormone-sensitive cancer. However, despite many years of effort, the effects on human health of long-term environmental exposure to EDs, whether singly or as mixtures, remain unknown.