This paper used quantitative approach to examine the relationship between six contingent factors that influence the Libyan agricultural firms to practice cost accounting systems. The available literature focused on the practice of cost accounting systems in manufacturing and servicing firms, this study filled the gap in the literature in term of studying the factors that influence the cost accounting practices in the agricultural firms. A questionnaire survey was used to collect data from 227 respondents, and the response rate was 81% (184). It was found that there is a positive relationship between the size, competition, legal obligation, and importance of cost information and practice of cost accounting systems, while the relationship between product diversity, cost structure and practice of cost accounting systems was found to be not significant.