This article investigates the nature of the linkages between trade and labor rights in developing countries. Specifically, we hypothesize that a “California effect” serves to transmit superior labor standards from importing to exporting countries, in a manner similar to the transmission of environmental standards. We maintain that, all else being equal, the labor standards of a given country are influenced not by its overall level of trade openness, but by the labor standards of its trading partners. We evaluate our hypothesis using a panel of 90 developing countries over the period 1986–2002, and we separately examine the extent to which the labor laws and the actual labor practices of the countries are influenced by those of their export destinations. We find that strong legal protections of collective labor rights in a country's export destinations are associated with more stringent labor laws in the exporting country. This California effect finding is, however, weaker in the context of labor rights practices, highlighting the importance of distinguishing between formal legislation and actual implementation of labor rights.