This research mainly aimed at assessing the relationship between selected microeconomic variables and a firm’s performance. This is a case study of the Mwea Rice Mills Limited, a rice manufacturer in Kirinyaga County. The specific objectives were to relate demand, rate of wages, prices and the performance of such firms. This study was descriptive in nature and used primary data obtained through questionnaires for the primary data. The study used the multiple regression analysis to draw the relationship between these independent variables and how an organization performs. The random sampling technique was used to sample data. Demand for goods and services was measured based on the consumer’s disposable income. To measure prices, this study put into consideration the cost of production and Job group qualifications for wages. The firm’s performance was measured by its efficiency in performance, a non-financial measure of performance. Given the focus was on various micro economic variables, this study also addressed how these variables are interrelated and the extent of their impacts.