Kenya is the third largest tea producing country in the world. About 10% of the global tea production comes from Kenya. For Kenya itself, this represents approximately 25% of its total agricultural export income. Tea production in Kenya is predominantly in the ownership of smallholders. Around 550.000 smallholders produce 60% of the total tea production of the country. Many societal costs occur during production, such as use of scarce water and forced adult and child labour. This study shows that the majority of the external costs of conventional tea cultivation exists of social costs (79%), of which 29% are due to underpayment of hired and family workers.