Good essay writing skills are necessary for composing correspondences, reports, term papers, research papers, homework, examinations and lots more. Essay writing provides the avenue for people to express themselves in a logical manner, develop their writing skill, vocabulary and grammar. Hence, its inclusion at all levels of the school curriculum of English as a foreign language (EFL) teaching in Nigeria. Despite the good intention of the curriculum planners, adult learners still perform poorly in the task as well as similar exercises after being taught, which is worrisome considering the predominant need for good essay writing skills in school and post school existence. This paper examines the causes of the difficulty which adult learners encounter that result in their inability to write acceptable essays during assessments and post school living. A questionnaire was used for data collection, and the conclusion of the findings is that students lack the basic motivation for understanding the topic due to non-realization of the importance of the topic. It recommends that teachers create the awareness of the relevance of Essay Writing among adult EFL learners prior to teaching them the topic as well as giving them essay topics which are specific to their courses rather than general ones.