The impact of a change in a District Health Authority's hospital medication discharge policy, from 14 to 7 days supply, was evaluated. This coincided with a revised initial discharge letter (prescription and clinical details combined). There was no significant difference between a 14 and 7 day supply with regard to whether GP's received an initial discharge letter, the number of days the letter took to arrive at the GP's surgery, the necessity for further treatment, or problems encountered in the continuity of a patient's treatment. However there was a significant improvement (P less than 0.01) in the quality of information on the new discharge letter as perceived by GPs. Provided the initial discharge letter has prescription details and is given to the patient to deliver to their GP, seven days supply of medication is sufficient.