A study carried out with first year students on a Diploma in Nursing programme at Nottingham University School of Nursing revealed that some students were struggling with basic arithmetic. A group was subsequently set up to address a range of issues relating to mathematics in nursing and nurse education. One of the areas investigated by the group was minimum entry requirement to the Diploma programme. In particular we wanted to determine the reliability of Mathematics GCSE Grade C as an indicator of arithmetic competence.Academic grades in mathematics (achieved prior to attendance at the School of Nursing) were compared with scores in an arithmetic test administered to students upon commencement on the Diploma in Nursing programme. It was found that the performance of students with Mathematics GCSE Grade C varied widely and some students could not solve basic arithmetic problems without the aid of a calculator.Schools of Nursing which adopt a policy of minimum qualifications in mathematics should not be complacent in assuming that students will be competent at arithmetic. The implementation of a programme of early assessment and tutorial support throughout the Diploma in Nursing programme is also recommended.