ABSTRACT The study investigated the effect of taxes on performance of small scale businesses in Bujumbura. The following objectives guided the study: i) to find out the effect of the tax mode of assessment on the performance of small scale businesses in Bujumbura; ii) to find out the effect of the tax mode of collection on the performance of small scale business in Bujumbura; and iii) to find out the effect of the legal tax penalties on the performance of small scale business in Bujumbura. The study used cross~sectiona1 research design. The target population was 1 60 business owners and managers. The sample was 114 respondents though only 100 respondents successfully paliicipLlted. The main research instrument was questionnaires and data was analyzed using frequency and percentages, mean and linear regression analysis. The study revealed that tax mode of assessment significantly affect performance of small scale businesses (R2=0 065 p=O.Ol 1). In addition, the study revealed that tax mode of collection significantly affect performance of small scale businesses (R20.476, pO.000). Lastly, the study revealed that legal tax penalties significantly affect performance of small scale businesses (R2=0.194, pO.000). The study made the following conclusions: tax mode of assessment significantly affects the performance of small scale businesses in Bujumbura; tax mode of collection significantly affects the performance of small scale businesses in Bujumbura; legal tax penalties significantly affect the pcrformai~ce of small scale businesses. The study made the following recommendations: small scale business owners should use accounting software in the assessment and management of their business tax liabilities in order to minimize the time and energy used in the tax management and therefore enables the use of those resources to increase the performance of their business. Furthermore, tax officers should increase their visits to business premises so as to provide a better understanding of tax obligations and tax procedures, an occasion to answer questions that small scale businesses owners may have and, in that way, help to increase the awareness of small scale businesses owners about their tax liabilities which decreases tax penalties and therefore positively affect the small scale businesses performance. Lastly, the tax body of Buruncli should review the rate of tax interest on unpaid tax liability in order to reduce the negative effect of taxes obligations and penalties on small scale businesses performance.