This paper reviews the documentation and coding of External causes of admitted fall cases in a major hospital. Intensive analysis of a random selection of 100 medical records included blind re-coding in the International Statistical Classification of Diseases and Related Health Problems, Tenth revision, Australian Modification (ICD-10-AM), Fifth Edition for External causes to ascertain whether: (i) the medical records contained sufficient information for assignment of specific External cause codes; and (ii) the most appropriate External cause codes were assigned per available documentation. Comparison of the hospital data with the state-wide Victorian Admitted Episodes Database (VAED) data on frequency of use of External cause codes revealed that the index hospital, a major trauma centre, treated comparatively more falls involving steps, stairs and ladders. The hospital sample reflected lower usage, than state-wide, of unspecified External cause codes and Other specified activity codes; otherwise, there was similarity in External cause coding. A comparison of researcher and hospital codes for the falls study sample revealed differences. The ambulance report was identified as the best source of External cause information; only 50% of hospital medical records contained sufficient information for specific code assignation for all three External cause codes, mechanism of injury, place of occurrence and activity at time of injury. Whilst all medical records contained mechanism of falls injury information, 16% contained insufficient details, indicating a deficiency in medical record documentation to underpin external cause coding. This was compounded by flaws in the ICD-10-AM classification.