Statistical Process Control (SPC), which is one of the stages of quality control, enables the collection and analysis of data related to processes in product and service production, the identification of variables affecting production, their interpretation within specified parameters, and the prevention of production errors.  In this research, quality control data from a company engaged in microbial fertilizer production were analyzed using control charts from Statistical Process Control techniques with the help of the Minitab 19 program, and p-defect rate charts and np-defect count charts were created. The selection of the graphs under investigation within the control charts stems from the data structure and the production stages and methods of the control samples taken in microbial fertilizer production.  A 24-week production process for the company under study was examined, and it was observed that 87.5% of production was within control limits. During production periods outside the control limits, it was determined that the errors in production were not systematic and that production generally occurred within the company's production specifications.  Conversely, considering that a 12.5% production loss in terms of output represents a significant rate in terms of efficiency and that production specifications may change during periods of intense competition, one of the research's recommendations is that quality control processes aimed at resolving errors at their source should continue on a continuous basis.