This study aimed to determine if patients can set their own educational priorities accurately and if the impact of diabetes education on knowledge differed between patients who did and did not set their own priorities. Forty patients referred for individual education were randomly assigned to one of two groups. Prior to education with a diabetes specialist nurse (DSN) patients ranked 10 diabetes care topics in order of perceived importance and relevance to their needs and completed a knowledge questionnaire. Group 1 set their own priorities and the DSN directed education according to the patients stated priorities. In Group 2 the DSN set the educational priorities without seeing the patients priority list. The priority ranking by the two groups of the 10 topics and their pre-education knowledge score were not significantly different. Post-education knowledge scores improved equally and significantly in both groups (Group 1 from 23 to 87%; Group 2 from 21 to 79%); P < 0.0001). In both groups, knowledge scores for the top three priorities were significantly higher than for the three lowest ranked topics. Knowledge is neither dependent on, nor a good discriminator of, patient-selected priorities. There may be reasons why it is important for patients to set their own priorities, but education directed solely at those priorities may leave knowledge deficits which could compromise diabetes care.