It is frequently held that the old "official" unions have largely been discredited, while numerous studies point to employee dissatisfaction with the performance of unions new and old in the era of transformation in Central and Eastern Europe. Nevertheless, membership has not collapsed, although the unions themselves exaggerate its total. It is somewhat surprising therefore that little work has been undertaken on the determinants of the individual union-joining decision in the new environment. This paper undertakes such a study for the case of Poland. Notwithstanding reputation effects, two further forces have accompanied the collapse of the communist regime and are likely to have reduced the attractiveness of union membership to workers. The first is the widespread loss of the distributive role with regard to important private goods which the unions previously possessed, while the second is the challenge to the strength of the social custom of union membership which systemic change has occasioned. While the transition economies are often held to have a distinct industrial relations system, in Poland at least, the determinants of the individual union-joining decision appear very similar to those which have been uncovered in western contexts.