In Uganda, taxation is the critical source of revenue, which has been used to provide public services to the citizens. However, taxation among the informal business sectors like SACCOs is still a pressing issue. The primary objective of this study was to evaluate the determinants of tax compliance among savings and credit cooperative organizations in Mbarara City, Western Uganda. The study sought to examine the influence of the determinants (tax system, tax compliance cost and tax deterrence sanction) on tax compliance (submission of returns, payment of taxes and tax reporting). The finding of the study revealed that tax system, tax compliance costs and tax deterrence sanction were statistically significant related with tax compliance among SACCOs. The result of this study also revealed that out of three explanatory variables incorporated in the model, two variables such tax system and tax deterrence sanction were significant predictors of tax compliance. The study concluded that tax compliance among SACCOs was significantly influenced by tax system and tax deterrence sanctions compared to tax compliance costs. In this regard, tax policy makers, Uganda Revenue Authority, Uganda Microfinance Regulatory Authority, tax enforcers, managers of different companies need to consider proper education channels, tax sensitization programmes, modern electronic registration of tax payers, best assessment methods and reduce compliance costs to motivate tax payers to voluntarily comply with tax filing, registration and payment.