Objective This study evaluated a patient's likelihood of a fall using information available at the time of presentation to a short-stay acute medical unit (AMU) with a high patient turnover rate and estimated the effect of within-unit bed moves on the occurrence of in-patient falls. Methods This study was a 3-year retrospective cross-sectional study of 28713 consecutive admissions comparing patients who fell and patients who did not fall. Factors assessed included premorbid falls risk factors, presenting issues and within-unit bed moves. Logistic regression was used to identify factors associated with patients who fell. Each admission was treated as a unit of measure. Results Of 28713 admissions, 182 (0.6%) involved at least one fall event. The fall rate was 5.67 falls per 1000 occupied bed days. Premorbid cognitive impairment (odds ratio (OR) 4.88), a presenting issue of confusion (OR 2.92) and a fall immediately before admission (OR 2.49) were associated with patients who fell (all P<0.001). Each bed move corresponded to a 27% increase in the odds of a fall (OR 1.27; P=0.027). Conclusion Premorbid cognitive impairment was the strongest risk factor for an in-patient fall on the unit. Within-unit bed moves significantly increased the risk of an in-patient fall and should be minimised. What is known about the topic? In-patient falls can cause significant patient harm at cost to the health system. There is limited research examining the association between within-unit bed moves and falls in a short-stay AMU. What does this paper add? Care in the short-stay AMU is complex and the number of bed moves is a modifiable factor that can reduce a patient's risk of an in-patient fall. What are the implications for practitioners? Bed moves need to be minimised, especially for patients with cognitive impairment. If bed moves are inevitable, operational plans can be designed to mitigate the increased risk caused by these moves.