In the fourth of this six-part series on nurse prescribing, Susan Davis assesses the advantages and disadvantages of patient self-administration of medicines in hospital. The former, she asserts, considerably outweigh the latter; a controlled self-administration programme can hasten a patient's progress towards full independence and ease the often difficult transition period following discharge. The problems experienced by specific groups of patients such as those with visual or manual dexterity deficits are considered and guidelines for practice offered.