Each of the contextual variables under study is associated with a significant lore about their impact on the ability of manufacturers to implement various lean manufacturing practices. The conventional wisdom associated with unionization is that it is encumbering; that progress toward lean production is very difficult in the presence of unionized work force. Our findings do not bear out this contention. In fact, for 16 out of 22 lean practices there was no significant difference in the likelihood of implementation between union and non-union plants. However, the six practices that unionized plants are less likely to implement include “cross-functional workforce,” a particularly thorny issue for plants with inflexible work rules imposed by collective bargaining agreements. Although the findings that we report suggest that having a unionized workforce is generally not a good reason for neglecting lean practices, certain practices are observed less frequently in a union environment.