This paper uses an amended sustainable livelihood framework to analyze the relationships between participation in the sustainability certification of the Round Table on Sustainable Palm Oil and smallholders livelihood.Our research reveals that social and human capital are pivotal in the relationship between certification and livelihood outcome.Through new organizational relationships the farmers get access to training,valuable relationships,and technology,which enables them to improve the amount and the quality of their production.The income effects are considered as the main motivation of smallholders to participate,while creating a more sustainable agriculture is not fully understood by most of smallholders.Certification does not change uncertainties related to premium fee,price volatility,market access,and access to credit,which might lead to suboptimal effects of participation in the certification.