This paper tests a number of hypotheses about the failure rates of worker cooperatives created in Atlantic Canada between 1940 and 1987. The event-history analysis shows that failure rates vary significantly by organizational age, sectoral location, and period of organizational founding, reflecting the effects of the business cycle and organizational population dynamics. In contrast to most conventional business organizations, worker cooperatives are not likely to fail during their early years of existence, but are most vulnerable in their fifth year.