The main aim of this research is to explore the Clinical and therapeutic characteristics of hospitalized patients with diabetes in England and Wales. We conducted an ecological study during the period 1999 – 2021. Hospital admission data for patients from all age groups were extracted from database in England (Health and Social Care Information Centre (HSCIC); Hospital Episode Statistics) and the Patient Episode Database for Wales (PEDW) for the period between April 1999 and April 2021 (NHS Wales Informatics Service; Annual PEDW Data Tables). Rates of hospital admission with their 95% confidence intervals (CIs) were calculated using the number of diabetes admissions for each age group divided by the mid-year population of the same age group of the same year. Diabetes mellitus medication prescription rates were calculated using the number of diabetes mellitus medication prescriptions divided by the total mid-year population during the same year. The Chi-squared test was used to assess the difference between the admission rates in 1999 and 2020 and the difference between diabetes mellitus medication prescription rates in 2004 and 2020. Our study detected a significant increase in the rate of diabetes mellitus medications prescription in England and Wales,representing a rise in diabetes mellitus medications prescription rate of 105.9% between 2004 and 2020. This increase was concomitant with the increase in diabetic hospital admission rate by15.2% over the past 15 years. Conclusion: The rate of hospitalisation due to diabetes mellitus has increased in England and Wales during the past two decades.