Error analysis is a significant procedure used in English language to identify errors. The present study identifies various errors committed by intermediate medical students studying in the government college of Pakistan in their written English essays. It aims to explore and explain the most frequently committed errors in the English compositions of students. The current study uses English Essays as an instrument of data collection from a sample of 50 students studying in Government Agha Nizamuddin Girls Degree College Sukkur. Data was analyzed following three step process as designed by Corder’s (1967) theory of Error analysis. Findings from the data analysis informed the researcher that students of aforementioned colleges commit errors in spelling, subject-verb agreement and use of tenses most frequently followed by misappropriate use of singular/plural, preposition, infinitives, word order and possessives.