Observations of pillar failures in Canadian hard-rock mines indicate that the dominant mode of failure is progressive slabbing and spalling. Empirical formulas developed for the stability of hard-rock pillars suggest that the pillar strength is directly related to the pillar width-to-height ratio and that failure is seldom observed in pillars where the width-to-height ratio is greater than 2. Two- dimensional finite element analyses using conventional Hoek-Brown parameters for typical hard-rock pillars (Geological Strength Index of 40, 60 and 80) predicted rib-pillar failure envelopes that did not agree with the empirical pillar failure envelopes.