<em>The purpose of the present study was to examine errors of written academic essays of Fijian undergraduate pre-service and in-service students at the Fiji National University Lautoka campus. Previous studies have focused only on pre-service undergraduate students but this paper takes into account in-service students as well which is a new dimension and knowledge to existing literature. The study mainly focused on eighteen errors as classified and adapted from Darus and Ching (2009) with the top six errors discussed in this paper. Twenty writing samples were analysed with the top errors for pre-service students being mechanics, subject verb agreement, redundancy, prepositions, tense and vocabulary choice while in-service students had errors in mechanics, redundancy, tense, articles, incomplete structures, word form and clarity. The authors found that carelessness and failure to recognize important words in the sentences as the main reasons for the errors. The paper recommends that remedial lessons on usage of articles, word formation, and prepositions are required in the course curriculum to improve upon the areas mentioned.</em>