Objective To explore the effectiveness of a patient education programme for chronic disease self-management in terms of whether (a) patients are taught to perform the medical procedure and (b) nurses have evidence of patients’ proficiency when they start self-management. Methods Patients were followed through an education programme for oral anticoagulation therapy, involving the use of INR-monitors. Training sessions were video-recorded and analyzed using Conversation Analysis. 55 instructional opportunities were identified, and the relationship between instructional response and patients’ subsequent (un)successful demonstration of the procedure traced. Results Patient errors provide the most frequent type of instructional opportunity, but not all are addressed; a significant number is allowed to pass uncorrected. Consequently, patients are not given the opportunity to learn. In the majority of cases where instructional opportunities are missed, patients subsequently do not demonstrate a correct understanding of the procedure. Conclusion Patients are allowed to start self-management although nurses do not have evidence that they are capable of performing all aspects of the medical procedure correctly. Practice implications Effective practice suggests that nurses take measures to minimize the amount of missed instructional opportunities that arise and ensure that errors are pursued until patients demonstrate proficiency in all aspects of the procedure.