Process capability indices (PCIs) are mainly used in industry in order to measure the capability of a process to produce products meeting specifications. Traditionally, the specifications are defined as crisp numbers. Sometimes, specification limits can be expressed as linguistic terms. Traditional PCIs can not be applied for this situation. In this paper, PCIs are analyzed under fuzzy environment. The fuzzy process capability analyses are developed when the specifications limits are represented by triangular and trapezoidal fuzzy numbers. The developed approaches are applied to teaching processes and the fuzzy PCIs are compared based on two different fuzzy ranking methods.