A Research Report Submitted in Partial/Fulfillment of the Requirements for Award of the Degree of Masters of Accounting and Finance (Msc A&F) of Mzumbe University.This study investigated whether the budget as a tool for decision making could enhance organisation performance by using Mount Meru University (MMU) which is in Arusha regional Tanzania as a case study. The objectives of the study were; to explore decisions made from the budget at MMU, to assess the effectiveness of the decisions made at MMU and to evaluate the organisation performance. The population of the study was MMU employees and students that were about 1,060. Employees were 210 and students were 850, the sample size of the study was 160 respondents which comprised 75 employees and 85 students. Primary and secondary data were collected through questionnaires and interviews, while documentary review was used to collect secondary data. The collected data were analyzed through the Statistical Package for Social Sciences (SPSS) and excel software. The general findings revealed that MMU did not give considerable weight to its budget decisions as it was revealed by employees 75 percent, and financial decisions did not always consider the budget 69 percent, while the performance of the organisation was found poor through employees and students who were not satisfied with most of the services, whereas the profits decreased from 2010 to 2011 by 138 percent and 188 percent from 2010 to 2012. Therefore, it was recommended that the management should learn to use the budget in a disciplinary manner in order to avoid unnecessary misuse of funds that lead to the organisation performance to be poor.