Rapid growth in private sector herbicide imports has led to a dramatic rise in use of commercial herbicides by Malian smallholder farmers. Given weak regulatory capacity to monitor markets, the recent proliferation in herbicide products and brands has been accompanied by widespread sales of unregistered products. We test the effects of herbicides applied to Mali’s major dryland cereals, sorghum and maize, on yield and labor productivity, differentiated by gender and age. We employ a multivalued treatment model with data collected from 623 households and 1273 plots. Findings show negative effects of unregistered herbicides on yields. In contrast, the use of registered herbicides enhances labor productivity of adult male and children. However, we find no significant effects on registered herbicides on yields or labor productivity of women.