Background: The transition from hospital inpatient care to medical care in the community is a high-risk period for adverse events. Inadequate communication, including low-quality or unavailable discharge summaries, has been shown to impact patient care. Aims: To assess use of abbreviations in clinical handover documents from inpatient hospital teams to general practitioners (GP), and the interpretation of these abbreviations by GP and hospital-based junior doctors. Methods: This is a retrospective audit of 802 discharge summaries completed during a 1-week period in 2017 by a Queensland regional health service. GP and local junior doctors then attempted interpretation of 20 relevant abbreviations. Results: A total of 99% (794) discharge summaries included abbreviations. A total of 1612 different abbreviations was used on 16 327 occasions. The median number of abbreviations per discharge summary was 17 (range 0–86). A total of 254 GP and 62 junior doctors responded to a survey, which found that no abbreviation was interpreted the same by all respondents. GP and junior doctors were unable to offer any interpretation in 17.9% and 15.2% of cases respectively. GP offered a greater range of interpretations than junior doctors, with a median of 9 and 3 different interpretations per abbreviation respectively. A total of 94% (239) of GP felt that the use of abbreviations in discharge summaries had the potential to impact patient care. A total of 152 (60%) GP felt that time spent clarifying abbreviations in discharge summaries could be excessive. Conclusions: Abbreviations are often used in discharge summaries, yet poorly understood. This has the potential to impact patient care in the transition period after hospitalisation.