Process Capability Indices (PCIs) are appropriate tools in order to measure the inherent capability of a process. In statistical process control, there are some uncertainties in data, such as uncertain specification limits and data. In these cases, fuzzy logic can be employed to manage the uncertainties. There are some researches about fuzzy process capability indices and in this paper; we present a review of fuzzy process capability indices and the related methodologies for fuzzification. Finally, recommendations are made to fuzzificate other process capability indices with more excellent specifications.