Around 1 in 10 of all cancer cases occur in adults of reproductive age. Cancer and its treatments can cause long-term effects, such as loss of fertility, which can lead to poor emotional adjustment. Unmet information needs are associated with higher levels of anxiety. US research suggests that many oncologists do not discuss fertility. Very little research exists about fertility information provision in the United Kingdom. This study aimed to explore current knowledge, practice and attitudes among oncologists in the United Kingdom regarding fertility preservation in patients of child-bearing age. A national online survey of 100 oncologists conducted online via medeconnect, a company which has exclusive access to the doctors.net.uk membership of GMC registered doctors. Oncologists saw fertility preservation (FP) as mainly a women's issue, and yet only felt knowledgeable about sperm storage, not other methods of FP; 87% expressed a need for more information. Most reported discussing the impact of treatment on fertility with patients, but only 38% reported routinely providing patients with written information, and 1/3 reported they did not usually refer patients who had questions about fertility to a specialist fertility service. Twenty-three per cent had never consulted any FP guidelines. The main barriers to initiating discussions about FP were lack of time, lack of knowledge, perceived poor success rates of FP options, poor patient prognosis and, to a lesser extent, if the patient already had children, was single, or could not afford FP treatment. The findings from this study suggest a deficiency in UK oncologist's knowledge about FP options and highlights that the provision of information to patients about FP may be sub-optimal. Oncologists may benefit from further education, and further research is required to establish if patients perceive a need for further information about FP options.