Following the creation of the decision matrix, the first step in MCDM methods is the normalization process. Normalization is one of the most important processes in MCDM methods, and it has an effect on MCDM ranking results. Therefore, choosing the appropriate normalization technique is very important in decision problems. This study aims to reveal the effect of normalization techniques on CoCoSo method results under different scenarios and select a suitable normalization technique. The study determined that N3, N4 and N6 normalization techniques can be used as alternatives to the max min normalization technique in the algorithm of the CoCoSo method. It was also determined that N1 and N2 normalization techniques are not suitable for the CoCoSo method. In this study, the suitability of different normalization techniques for the CoCoSo method was tested for the first time.