One very important function for managers are making decisions. In particular, becausethe decision may have a great impact at both the individual and organizational level.Therefore, it is crucial for managers to have accurate information for makingappropriate decisions. This research studies ways cost information could helpmanagers make appropriate decisions regarding the business performance ofmanufacturing companies located in northeast Thailand, It seeks to compare howmanagers use cost information for making decisions in firms with different amounts ofcapital, different ages, different total assets, different annual revenues, and a differentnumber of employees. It also compares the business performance of firms withdifferent amounts of capital, total assets, and annual revenues. A questionnaire wasused to collect data from 143 top managers in manufacturing firms. The response ratewas approximately 43.33 percent. Mean and one-way ANOVA were used to analyzethe data. Results indicate that managers found cost information was important formaking decisions. There were no differences in decision making between managers inbusinesses with different amounts of capital, different ages, different total assets,different annual revenues and number of employees. In addition, statistical tests showthat there were significant differences in terms of business performance between firmswith different amounts of capital, total assets, and annual revenues. Moreover,businesses that have different firm ages, and numbers of employees are not significantly different in business performance. The explanation is that businessperformance depends on employee efficiency and management more than number ofemployees and firm age.