As Cameroon is a country considered as emerging, it is characterized by an unfavorable business environment according to the General Census of Enterprises (RGE) carried out by the National Institute of Statistics (INS) in 2018 due to mismanagement. It is with the aim of improving the business environment that this article aims to analyze and highlight the effect of internal control on the effectiveness of SMEs in Cameroon context. To achieve this, we have opted for a hypothetic-seductive approach from which three hypotheses are formulated. An analysis of data collected from a questionnaire administered to 50 Cameroonian SMEs was made through descriptive analysis and explanatory analysis. Our results, after the explanatory analysis using the SPSS 20 software, show that compliance with the procedural guide and the internal regulation of SMEs significantly and positively influence the effectiveness of SMEs in Cameroon context. On the other hand, the System of Accounting Data, for its part, significantly and negatively influences the efficiency of SMEs in Cameroon context. These results allow us to support our hypotheses.