OBJECTIVES: To characterise UK Cancer Drug Fund (CDF) scoring of breast cancer drugs using the CDF prioritisation tool and to assess the final decisions made by the Chemotherapy Clinical Reference Group (CCRG) and the national CDF panel. METHODS: The CDF decision summaries (available online at www.england.nhs.uk/ourwork/pe/cdf/cdf-drug-sum) record the formal decisions of the CCRG in relation to drugs and drug indications that are reviewed for inclusion on the national CDF list. We reviewed the individual scoring for each treatment in the criteria using the CDF prioritisation tool. Assessed criteria included: magnitude of survival benefit (progression free survival and overall survival), quality of life, toxicity compared with existing therapies, degree of unmet clinical need, strength of evidence and total score. RESULTS: Between April 2013 and May 2015, 15 decision summaries assessing 7 drugs for the treatment of breast cancer were reported by the CCRG. Of these summaries, 5 saw a positive overall decision and 10 were negative. The overall scoring of drugs varied considerably, with scores ranging from 1 to 13 and with just under half of drugs (7/15) receiving a score of 1 or no score at all. In contrast, the quality of evidence provided by manufacturers varied to a much lesser extent, with the majority of drugs receiving a score of “B” which, according to the scoring system, indicates one good-quality published Phase III randomised controlled trial. CONCLUSIONS: Understanding the way the UK CDF makes decisions on the provision of breast cancer treatments can help pharmaceutical companies prepare evidence in order to maximise market access. Identifying strengths and weaknesses in the scoring of previous submissions to the CDF can also optimise submissions to give patients with breast cancer the best chance of access to innovative medicines.