Medication errors can lead to adverse outcomes such as increased mortality, increased duration of hospitalization, and increased medical expenses. Error is a measure of the estimated difference between the observed or calculated value of a quantity and its true value. Errors are an integral part of human life. Many errors originate from the natural process of cognitive and behavioural adaptations which develop the correct behavioural skills, and cognitive skills are essential to administer the medication for safety of the patient. Material and Methods: The quantitative research approach with exploratory survey research design was conducted during one month of December to January 2016.A total 496 events of medication administration via oral, intramuscular, intravenous, and subcutaneous route, from 39 staff nurses were observed through observational checklist in medical, surgical, obstetrical and gynaecological wards, during morning, evening, night shift and events were selected by event sampling technique. Result: Majority of staff nurses were professionally qualified up to diploma. Maximum 42.7% medication error in obstetrical and gynaecological ward, followed by 38.8% errors were found in subcutaneous route of surgical ward, 35.1% and 34.2% error were found in intramuscular route of obstetrical and gynaecological ward. In transcribing error, 72.8% of medication errors were observed in oral route in evening shift of surgical ward, in monitoring error, 48.1% of medication errors were observed in intramuscular route in morning shift of obstetrical ward. There was no association observed in selected wards with selected variables. The findings shows medication errors were independent of personal and situational variables.