ObjectivesStudent assistantships are recommended to prepare medical graduates for clinical practice. Traditionally, assistantships have consisted of longer placements, often up to 15 weeks. However, within the constraints of the final year, medical schools need to carefully balance the time required for specialty placements, assessments and the risk of student burnout. We set out to evaluate the effectiveness of shorter, personalised student assistantships.DesignAn evaluative study on the changes in final year student confidence in preparedness for practice after a 3-week assistantship with defined learning objectives and learning needs assessment.SettingEight hospitals affiliated with Imperial College School of Medicine.OutcomesStudent confidence in 10 learning outcomes including organising ward rounds, documentation, communication with colleagues, communication with patients and relatives, patient handover, practical procedures, patient management, acute care, prioritisation and out-of-hours clinical work.ResultsTwo hundred and twenty final year medical students took part in the student assistantship, of whom 208 completed both the pre-assistantship and post-assistantship confidence rating questionnaires (95% completion rate). After the assistantship, 169 (81%) students expressed increased confidence levels in one or more learning objectives. For each individual learning objective, there was a significant change in the proportion of students who agreed or strongly agreed after the assistantship (p<0.0001).ConclusionOverall, the focused 3-week, personalised student assistantships led to significant improvement across all learning objectives related to preparedness for practice. The use of the pre-assistantship confidence rating questionnaire allowed students to identify and target areas of learning needs during their assistantship.