This paper places on record the clinical activity of the hospital facilities run by 22 Field Hospital on Exercise SAIF SEREEA II in Oman from August to November 2001. There were 1322 episodes of illness resulting in a hospital admission. The mean rate of admission was 1.96 patients per thousand per day (SD 13.62). The main causes of admission were gastrointestinal illness, conditions related to the heat and injuries. The reporting of health service utilisation data is an important duty of medical personnel during overseas deployments in order to add to the dataset available for the estimation of medical workload for future operations.