The knowledge of medication errors is an essential prerequisite for better healthcare delivery. The present study investigated prescribing errors in prescriptions from outpatient departments (OPDs) and emergency wards of two public sector hospitals in Lahore, Pakistan. A manual prescription system was followed in Hospital A. Hospital B was running a semi-computerised prescription system in the OPD and a fully computerised prescription system in the emergency ward. A total of 510 prescriptions from both departments of these two hospitals were evaluated for patient characteristics, demographics and medication errors. The data was analysed using a chi square test for comparison of errors between both the hospitals. The medical departments in OPDs of both hospitals were the highest prescribers at 45%-60%. The age group receiving the most treatment in emergency wards of both the hospitals was 21-30 years (21%-24%). A trend of omitting patient addresses and diagnoses was observed in almost all prescriptions from both of the hospitals. Nevertheless, patient information such as name, age, gender and legibility of the prescriber's signature were found in almost 100% of the electronic-prescriptions. In addition, no prescribing error was found pertaining to drug concentrations, quantity and rate of administration in e-prescriptions. The total prescribing errors in the OPD and emergency ward of Hospital A were found to be 44% and 60%, respectively. In hospital B, the OPD had 39% medication errors and the emergency department had 73.5% errors; this unexpected difference between the emergency ward and OPD of hospital B was mainly due to the inclusion of 69.4% omissions of route of administration in the prescriptions. The incidence of prescription overdose was approximately 7%-19% in the manual system and approximately 8% in semi and fully electronic system. The omission of information and incomplete information are contributors of prescribing errors in both manual and electronic prescriptions.