This study assesses income and poverty effects of vegetable commercialization in Kenya with a special focus on gender issues and evaluates the performance of institutional arrangements that link small producers to the high-value vegetable supply chains. Using econometrics analysis of two rounds of rural household survey, the study reveals that the participation of smallholders in the domestic and export vegetable markets is declining. Weather risks, high costs of inputs and unskilled labour as well as erratic vegetable prices contribute to the declining trend. The impact evaluation of market participation reveals that households supplying the export market have a higher per capita income. The examination of gender roles indicates that the improvement of land productivity and the promotion of women’s access to agricultural training and extension services might enhance their market participation. The analysis of vegetable contractual arrangements indicates that the governance structure is important to the profitability and hence the sustainability of farmer-trader relationships.