Private standards are spreading rapidly in international food trade and are moving beyond food quality and safety aspect to address environmental and social concerns. Using panel data from own company and worker surveys and different econometric techniques, we analyze how the adoption of a variety of private standards, that differ with respect to their focus on labor standards, influences employment conditions in the horticultural export chain in Peru. We find that workers employed in companies adopting labor standards are more likely to be paid a minimum wage, to have a contract and to receive training, but there is no effect of private standards on the level of the wage and on the employment period. We conclude that labor standards are most effective in reinforcing the respect of national labor laws and when there exists a clear cut definition of the employment requirements they push forward.