Medicines are widely used to provide the best medical care to patients, which contributes to improving the health level of the community. Despite that, the use of medicines is accompanied by errors that cause harm in several aspects of health. this research aimed to explore the trend of hospital admission due to medication administration errors and their associated prescription pattern. An ecological study was conducted using hospital admission data that are publicly available. Data in this study was extracted from the Hospital Episode Statistics (HES) database in England and Wales from the Patient Episode Database in Wales for the duration between April 1999 and April 2020. The rate of annual hospital admissions related to medication errors increased by 32% [from 184.21 (95% CI 183.0 -185.4) in 1999 to 243.18 (95% CI 241.9-244.4) in 2020 per 100,000 persons. The most common three indications of hospital admissions related to medication error causes were: (non-opioid analgesics, antipyretics and antirheumatics, psychotropic drugs, antiepileptic, sedative-hypnotic and anti-parkinsonism drugs. The age group 15-59 years had the highest number of hospital admissions related to medication errors with 83.4% of the total admissions. Women contributed to 59.1% of the total hospital admissions related to medication errors. medication prescriptions rate increased by 43.3% [from 1,349,363.51 (95% CI 1,318,107.33-1,380,619.68) in 2004 to 1,933,721.77 (95% CI 1,898,373.17 - 1,969,070.38) in 2020 medication prescriptions per 100,000 persons, trend test, p<0.05]. Over sixteen years from 2004-to 2020, BNF Chapter 9 (Nutrition & blood), BNF Chapter 6 (Endocrine system), and BNF Chapter 15 (Anaesthesia) showed the highest increase in the rate of annual prescriptions which increased by 1.5-fold, 88.3% and 84.6%, respectively. There was a positive correlation between the admission rates and the prescription rates of their associated therapeutic classification for many causes of hospital admissions. More research is needed to identify high-risk populations and provide effective interventions to reduce the chance of developing complications that could lead to such admissions.